WHST.11-12.2Common CoreELAWriting in History, Science and Technical SubjectsGrades 11-12
WHST.11-12.2: Narrating a Historical Event as a Chain of Causes
In plain English: WHST.11-12.2 is the Common Core literacy standard that asks students in grades 11 and 12 to write informative and explanatory texts in history, science and technical subjects. Students organize complex ideas so that each new element builds on the one before, select the most significant facts, use analogy and precise terms to manage complexity, and write with a knowledgeable stance for their readers.
Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
a.Introduce a topic and organize complex ideas, concepts, and information so that each new element builds on that which precedes it to create a unified whole; include formatting (e.g., headings), graphics (e.g., figures, tables), and multimedia when useful to aiding comprehension.
b.Develop the topic thoroughly by selecting the most significant and relevant facts, extended definitions, concrete details, quotations, or other information and examples appropriate to the audience's knowledge of the topic.
c.Use varied transitions and sentence structures to link the major sections of the text, create cohesion, and clarify the relationships among complex ideas and concepts.
d.Use precise language, domain-specific vocabulary and techniques such as metaphor, simile, and analogy to manage the complexity of the topic; convey a knowledgeable stance in a style that responds to the discipline and context as well as to the expertise of likely readers.
e.Provide a concluding statement or section that follows from and supports the information or explanation provided (e.g., articulating implications or the significance of the topic).
Common Core State Standards for English Language Arts & Literacy · Domain: Writing Standards for Literacy in History/Social Studies, Science, and Technical Subjects 6-12 · Cluster: Text Types and Purposes · Official standard
Students learn to narrate a historical event the way a historian of technology explains it: not as a list of things that happened, but as a chain in which each cause sets up the next. The case is the Boston Molasses Flood of January 15, 1919, when a storage tank in the North End burst and a wave of molasses killed 21 people. The event joins history and engineering: a company's decisions, a structure that was never adequately tested, a change in the weather, and a liquid that behaved in ways few people expected. Students study an original model text built as that chain, diagnose a weak draft, and then write their own explanation of the rescue and cleanup from a set of research notes. The facts on this page come from published accounts of the flood; no data are invented.
The lesson follows the five parts of WHST.11-12.2: introducing the topic and organizing complex ideas so that each new element builds on the one before, with headings, graphics and multimedia where useful (a); developing the topic thoroughly with the most significant and relevant facts for the audience (b); linking sections with varied transitions and sentence structures that clarify how complex ideas relate (c); using precise language, domain-specific vocabulary and techniques such as metaphor, simile and analogy, with a knowledgeable stance that fits the discipline and the readers (d); and ending with a conclusion that follows from the explanation, for example by stating its significance (e).
Learning Objectives
By the end of this lesson, students will be able to:
Organize an explanation of a historical event so that each section builds on the one before and the whole reads as a unified chain
Select the most significant and relevant facts for a named audience and justify what they leave out
Use an analogy, simile or metaphor to manage a complex idea, and state where the comparison stops working
Link sections with varied transitions and sentence structures that show cause, concession and sequence
Write with a knowledgeable, appropriately hedged stance and conclude with the significance of the topic
Prior Knowledge Required
Students should already be comfortable with:
Writing informative texts that make connections and distinctions in a discipline WHST.9-10.2
Analyzing whether earlier events caused later ones or simply preceded them RH.9-10.3
Using subordinate clauses and semicolons to join related ideas
Reading a short technical description that includes measurements
"In January 1919, a tank of molasses burst in Boston and the wave killed 21 people. List three questions a reader would need answered before this sounds like history rather than a strange news story."
Collect questions on the board and sort them into three groups: why the tank failed, why the syrup was so deadly, and what happened afterward. Tell students that a strong explanation answers these questions in an order where each answer prepares the next one. Ask: which group has to come first, and why?
Direct Instruction20 minutes
Explain the key phrase of standard a: an explanation is organized so that "each new element builds on that which precedes it to create a unified whole." Show Diagram 1, which lays out the model text as a chain of five links. Then work through the five examples below, which show the moves the model uses: an introduction that sets up the chain, facts chosen for their significance, a comparison that manages a complex idea, a sentence structure that shows a relationship, and a stance that is confident without claiming more than the evidence allows.
Introducing a topic and a unified plan
Vague draft opening: The Molasses Flood was a weird disaster that happened in Boston a long time ago. It names an event but gives the reader no question and no plan.
Result: Revision: The Molasses Flood of 1919 looks like a freak accident until its causes are placed in order; then it becomes a story about a tank no engineer checked and a liquid no one had reason to fear.
Selecting the most significant fact
Two true facts for a section on why the wave was so destructive: molasses is roughly 40 to 50 percent denser than water, and molasses was a common ingredient in baking.
Result: Keep the first: density explains how much energy the released syrup carried. The second is accurate but explains nothing about the wave, so it belongs in a different text.
An analogy that manages a complex idea
Readers need to know why the failure began near the base of the tank, not near the top.
Result: A liquid presses harder the deeper it is, just as a swimmer feels more pressure in the ears at the bottom of a pool than at the surface; the bottom of a full tank therefore carries the greatest load on its walls.
Varied syntax that shows a relationship
Two flat sentences: The syrup flowed fast at first. It thickened as it cooled.
Result: Revision: While the syrup first rushed out fast enough to knock down buildings, it thickened as it spread and cooled, holding fast whatever it had already reached. (A contrast clause shows that the two behaviors happened in turn and did different kinds of harm.)
A knowledgeable stance for the readers
Draft for a physics class: The tank just broke because it was bad.
Result: Revision: The walls were about half the thickness a 2014 analysis judged necessary, and cracks spread from rivet holes near the base, the point of greatest pressure; the added pressure from the new cargo is the likeliest final trigger, an inference rather than a measurement.
Read the model text once for the story, then a second time for its structure. Students write, in the margin next to each section, the question that section answers and the earlier section it depends on. Discuss the last section, "Why It Matters": it does not repeat the chain but says what the chain implies about responsibility and regulation. That is what standard e means by "articulating implications or the significance of the topic."
1Shortly after noon on January 15, 1919, a steel tank in Boston's North End split open and released about 2.3 million gallons of molasses. A wave of syrup, estimated at 15 to 25 feet high at its peak and moving at about 35 miles per hour, crushed buildings, drove steel from the tank against the girders of the elevated railway and killed 21 people; about 150 more were injured. The disaster is often retold as an oddity, but it is better understood as a chain: a tank built without proper testing, a sudden change in the load it carried, and the physical behavior of molasses itself. Each link explains why the next one proved so deadly.
2The Tank The tank belonged to the Purity Distilling Company, which the United States Industrial Alcohol Company (USIA) had bought in 1917. Molasses unloaded from ships was stored there and piped to a plant in Cambridge to be fermented into alcohol, a key ingredient in munitions. The tank, 50 feet tall and 90 feet across, was completed in 1915 without an adequate test: it was never filled with enough water to check for leaks. It leaked from the start, and the company painted it brown, which hid the seeping syrup instead of stopping it. Arthur Jell, the treasurer who oversaw its construction, had no training in engineering or architecture. A 2014 engineering analysis found that its steel walls were about half as thick as a tank of that size required.
3The Load A weak tank can stand for years if its load stays steady; in January 1919, the load changed. A ship had just delivered a fresh cargo of molasses, warmed so that it would flow during unloading, and the air warmed quickly from well below freezing to above 40 °F. Later analyses have suggested that warm molasses expanding inside the tank, and gas produced by fermentation, added pressure to walls that were already too thin. The failure began near the base, around a manhole, where cracks spread from rivet holes.
4The Wave Once the walls gave way, the molasses behaved in ways few people expect of a syrup. It is roughly 40 to 50 percent denser than water, so the full tank held an enormous store of energy. Like ketchup that resists the bottle until it is shaken and then rushes out, molasses flows more freely when it is pushed hard, and in the first seconds the wave moved fast enough to knock buildings off their foundations. As it spread across the cold streets, however, it cooled and thickened. A 2016 Harvard University study of how molasses thickens as it cools concluded that this rapid thickening hampered rescuers and left victims trapped. For anyone caught in it, the syrup had become less like a liquid and more like wet cement.
5The Reckoning USIA argued in court that anarchists had blown up the tank. After about three years of hearings, the court-appointed auditor, Hugh W. Ogden, rejected that claim and found the company responsible. Most accounts put USIA's total payments at about $628,000, though figures vary.
6Why It Matters The flood is remembered for its strangeness, but its significance lies in ordinary failures: a structure that no qualified engineer checked, warning signs treated as nuisances, and a hazard no one imagined because the material seemed harmless. Afterward, Boston began requiring engineers' and architects' calculations and signed, stamped drawings to be filed with building plans, a form of oversight by licensed architects and engineers. The flood remains an early lesson that the burden of proving a structure safe belongs to its builders.
SVHS lesson authors, Model explanatory text (history and technology): How a Tank of Molasses Killed Twenty-One People. Original passage written for this page.
Guided Practice15 minutes
Pairs fill in the table below for the model text. In the last column they name the words that tie each section to the one before it. Then they read the weak draft that follows, which a student wrote about the same event, and list its problems: organization, facts, comparisons, stance and conclusion. They revise part of it in Activity 3.
How each section of the model text (T1) builds on the one before
Paragraph
Section
Question it answers
Depends on paragraph (students fill in)
Linking words (students fill in)
1
Introduction
What happened, and how will it be explained?
2
The Tank
Why was the tank weak?
3
The Load
Why did a weak tank fail on that day?
4
The Wave
Why was the released molasses so deadly?
5
The Reckoning
Who was held responsible?
6
Why It Matters
What does the chain imply?
The Great Molasses Flood happened in Boston and it was really crazy. First the tank was built. Then it got warm. Then the tank exploded because anarchists put a bomb in it. Then a giant wave of molasses came out and it was like a monster eating the city. 150 people died. The molasses was sticky. Then there was a court case and the company had to pay. In conclusion, molasses is delicious but dangerous.
SVHS lesson authors, Weak draft for revision (history class): The Molasses Flood. Original passage written for this page.
Independent Practice20 minutes
Students read the research notes below on the rescue and the cleanup, drawn from published accounts of the flood. They number the paragraphs, mark each note as significant, useful background or not relevant to the question Why was the rescue so hard, and what did it take to clear the city?, and connect at least two notes to the behavior of molasses explained in the model text (T1, paragraph 4).
1The first rescuers to arrive were 116 cadets from the USS Nantucket, a training ship of the Massachusetts Nautical School that was docked nearby.
2The cadets waded into knee-deep molasses to pull out survivors, while others kept onlookers out of the rescuers' way.
3The Boston Police, the Red Cross, and Army and Navy personnel arrived soon after. Doctors and surgeons set up a makeshift hospital in a nearby building.
4Rescuers struggled to move through the syrup. The search for victims went on for four days, and some of the dead were so coated in molasses that they were hard to recognize.
5Some victims were swept into Boston Harbor and were not found until three to four months later.
6Cleanup crews washed the streets with salt water from a fireboat and spread sand to absorb the molasses. Cleaning the immediate area took weeks and involved several hundred people.
7Rescuers and sightseers tracked molasses across the city, onto subway platforms, streetcar seats and pay telephones. The harbor stayed brown with molasses until summer.
8For decades, residents reported that the neighborhood smelled of molasses on hot days.
9The Eighteenth Amendment, which led to national Prohibition, was ratified the next day, January 16, 1919.
10The tank stood on ground that is now Langone Park, which has a ball field. For the 100th anniversary in 2019, researchers surveyed the park with ground-penetrating radar and proposed a likely location for the tank's remains, though they did not dig to confirm it.
SVHS lesson authors, Research notes: The Rescue and the Cleanup, January 1919. Original passage written for this page.
Each student writes a plan for an explanation of the rescue and the cleanup: three headings in an order where each section builds on the one before, the most significant note for each section, and one comparison they could use to explain why the syrup trapped people. Collect the plans; students write the explanation for homework.
Closure5-10 minutes
Exit ticket: (1) Name one link in the model text's chain and the earlier link it depends on. (2) Write one sentence about the flood that uses a concession clause (although, even though, while). (3) In one sentence, state a significance of the flood that the model text does not state.
Teacher note on the sources: accounts of the flood differ on some details, such as the height of the wave (15 to 25 feet), the density of molasses, the timing of the last delivery and the amount the company paid; early newspaper reports gave lower death tolls than the final count of 21. The model text uses figures widely reported in published histories and hedges the causes that later analyses could only infer. Encourage students to hedge in the same way and to say where a figure is an estimate. Some students may find the accounts of victims distressing; treat the deaths with the seriousness of any other disaster.
Differentiation Strategies
For Struggling Students
Give sentence frames for linking sections: "Because ... , ... .", "Although ... , ... ." and "Once ... , ... ."
Provide the research notes with the significant notes already marked, so students can focus on ordering them
Let students build the chain as a flowchart like Diagram 1 before they write paragraphs
For Advanced Students
Ask students to write a paragraph for an engineering audience that explains why cracks at rivet holes near the base fit a tank loaded beyond its strength, with the pool analogy and its limits
Have students compare two published accounts of the flood and explain in a short note how their figures differ and which they would use
Ask students to write a second conclusion for the model text addressed to a city building department, and explain how the change of reader changed the significance they stated
Assessment Guidance
What to Look For
Check that the introduction names the event and sets up the order of the explanation, and that each section answers a question raised by the one before. Facts should be the most significant for the reader and the question, with at least one fact left out on purpose. Look for varied sentence structures that show relationships (subordinate clauses, semicolons, appositives), not only "then." A comparison should clarify one specific idea, and the writer should know where it stops working. The stance should be confident about what is established and hedged about what can only be inferred. The conclusion should state a significance or implication that follows from the chain.
02
Classroom Activities
3 Activities
1
Build the Chain: Fact Card Selection
15 minGroups of 3
Groups receive ten true fact cards about the flood, select the six most significant for the question Why was the Molasses Flood so deadly?, and arrange them so that each card builds on the one before. The activity builds standards a and b.
Fact Cards
1. A 2014 analysis found the tank's steel walls were about half as thick as a tank of its size required.
2. The tank stood on Commercial Street, next to Boston Harbor, where ships unloaded molasses.
3. The tank leaked from the start, and the company painted it brown.
4. A fresh cargo of warmed molasses had just been delivered.
5. On January 15, 1919, the air temperature rose quickly to above 40 °F.
6. An early front-page headline in the Boston Post reported 11 dead and 50 hurt.
7. Molasses is roughly 40 to 50 percent denser than water.
8. As the syrup cooled in the streets, it thickened quickly and trapped victims.
9. USIA bought the Purity Distilling Company in 1917.
10. After the flood, construction rules required oversight by licensed architects and engineers.
Procedure
Groups sort the cards into "explains why it was deadly" and "true but not needed for this question"
Teacher key: cards 1, 3, 4, 5, 7 and 8 explain the deadliness; cards 2, 6, 9 and 10 are true but answer other questions (location, early reporting, ownership, aftermath)
Groups arrange their six cards so that each card builds on the one before, then write one linking sentence between each pair of neighboring cards
Groups compare their order with Diagram 1 and defend any difference
Discussion Questions
Card 6 gives a death toll that differs from the final count of 21. Why must a writer be careful with early reports, and when might card 6 be worth including?
Card 10 does not explain the deadliness. For what other question would it be the most significant card?
Which of your linking sentences needed a word other than "then"? What relationship did it show?
2
Two Readers, One Wave
20 minGroups of 3-4
Groups rewrite the model text's section on the wave (T1, paragraph 4) for two different readers, choose a comparison for each, and plan the formatting, graphics and multimedia each reader needs. The activity builds standards a and d.
Audience Cards
Reader 1: a high school physics class that knows the words density, energy and viscosity (a liquid's resistance to flowing) and wants the mechanism
Reader 2: families visiting a museum exhibit about Boston history, including children about ten years old
Procedure
For each reader, groups rewrite the section in 80-120 words, choosing which facts from T1 to keep
Each version uses one comparison (analogy, simile or metaphor); groups write one sentence saying what the comparison explains and one saying where it stops being accurate
Groups plan the exhibit version as a panel: a heading, one figure with a caption, and one piece of multimedia (for example, a narrated map of the flooded streets), with a reason for each choice
Groups trade versions and judge whether each would suit its reader without misleading them
Discussion Questions
Which words did you have to define for the families but not for the physics class?
Did the physics version need a comparison at all? What did it gain or lose?
What makes a writer sound knowledgeable to experts, and what makes a writer sound knowledgeable to children?
Modification for Distance Learning
Groups draft in a shared document with one page per reader, and build the exhibit panel as a single slide. Each group records a 30-second voice-over for its panel and posts it with the slide.
3
From List to Unified Whole: Revision Lab
20 minPairs
Pairs revise the middle of the weak draft (T2) so that it reads as linked sections rather than a list, using a syntax and transition bank. The activity builds standards c and d.
Syntax and Transition Bank
Cause: because, since, as a result, which meant that, so that
Concession: although, even though, while, despite
Time as cause: once, when, as soon as, by the time
Structures: a subordinate clause before the main clause; a semicolon joining two linked independent clauses; an appositive that renames ("Arthur Jell, the company treasurer, ..."); a colon that introduces an explanation
Procedure
Replace "it was like a monster eating the city" with a comparison that explains one specific feature of the wave, and write one sentence saying what it explains
Develop "The molasses was sticky" into two sentences that explain why the syrup trapped people, citing T1, paragraph 4
Revise "Then there was a court case and the company had to pay" so that it names the finding and links it to the causes, using an appositive or a colon
Add headings so that the revised middle has at least two sections, and write the first sentence of each section so that it builds on the one before
Trade with another pair and label each structure from the bank that they used
Technical Report Variation
Pairs rewrite their middle section as the stage-by-stage account of the failure in an engineering incident report: numbered stages, precise terms (load, rivet, plate, manhole), measurements with units, and no comparisons. Students then explain which choices changed because the discipline changed.
03
Diagrams & Visual Aids
1 diagrams
Diagram 1: The Molasses Flood as a Chain of Causes
The model text is built as a chain of five links, one section for each. Each link depends on the one before it, and the words on the right name the relationship that the text's transitions must make clear. The final section, "Why It Matters," states what the whole chain implies.
04
Homework Assignment
~30 min
WHST.11-12.2 Homework: Explaining the Rescue and the Cleanup
Directions: Write an explanation of 400-600 words for readers of a city emergency-management training newsletter on this question: Why was the rescue after the Molasses Flood so hard, and what did it take to clear the city? Use the research notes (T3) in Independent Practice and the model text (T1). Cite as (T3, paragraph 4) or (T1, paragraph 4).
Part 1: Introduce and Select (Problems 1-2)
Write an introduction of three or four sentences that names the event, poses the question, and sets up an order for your explanation in which each section will build on the one before.
Your readers plan responses to disasters. List the notes from T3 you will use, ranked by significance for them. Name every note you will leave out and explain in one sentence why these readers do not need it.
Part 2: Develop and Organize (Problems 3-4)
Draft the body in two or three sections with headings. The first sentence of each section should show how it depends on the one before. Include one table or figure, with a title, that makes a sequence or comparison easier to follow, and explain in one sentence why it helps these readers.
Write one analogy, simile or metaphor of your own, not the model text's "wet cement," that explains why the cooled molasses made rescue so difficult. Then write one sentence explaining where your comparison stops being accurate.
Part 3: Link and Conclude (Problems 5-6)
Revise your body so that it uses at least three different sentence structures to link ideas (for example, a concession clause, a semicolon and an appositive). Underline each one and label the relationship it shows.
Write a concluding section of three or four sentences that states an implication of the rescue and the cleanup for emergency planners today. Then check your stance: mark one sentence that states an established fact and one that you hedged because it can only be inferred.
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
No Credit (0 pts)
Organization and Formatting
Introduction sets up the order; each section builds on the one before; headings and a titled table or figure aid comprehension
Sections present but in a list-like order, or formatting unhelpful
No clear order
Significant Facts
The most significant notes for emergency planners, accurately cited; omissions justified
Some notes irrelevant or uncited
Facts inaccurate or missing
Syntax, Transitions and Comparison
Varied structures show cause, concession and sequence; the comparison clarifies one idea and its limit is stated
Transitions mostly "then" or "also"; comparison vague
No links between ideas
Stance and Conclusion
Knowledgeable, hedged where needed, suited to the readers; conclusion states an implication that follows
Stance uneven, or conclusion only summarizes
Informal or no conclusion
05
Quiz: 20 Questions
Interactive, with answers
Instructions
The questions use the model text (T1) and the weak draft (T2) in the lesson plan. Your score updates as you answer, and Reset quiz clears everything so you or your students can try again.
Multiple choice: pick an option to check it. Short answer: write your answer, then reveal the model answer.
0 of 20 answered · 0 correct
Question 1 of 20 · Multiple Choice
Which assignment asks for the narration of a historical event under WHST.11-12.2?
Answer: B
B asks the writer to explain how an event unfolded and why, which is an informative/explanatory narration of a historical event. A and D ask the writer to take and defend a position, which is argument, and C asks for fiction, which is narrative writing rather than an explanation.
Question 2 of 20 · Multiple Choice
Which revision of the weak draft's (T2) opening sentence, The Great Molasses Flood happened in Boston and it was really crazy, best introduces the topic for a history reader?
Answer: A
A names the event, its time and place, and the question the explanation will answer, so it introduces the topic and sets up what follows. B replaces "crazy" with more exaggeration, C addresses the reader with a question instead of introducing the topic, and D opens with background that does not mention the event at all.
Question 3 of 20 · Multiple Choice
A writer wants to add a section on the rescue, based on the research notes (T3), to the model text (T1). Where should it go so that each new element builds on the one before?
Answer: D
The rescue section depends on paragraph 4, which says the thickening "hampered rescuers and left victims trapped," so it belongs right after it and before the court case. A puts an effect before its causes, B places new information after the conclusion, which should follow from everything before it, and C links sections by location rather than by cause.
Question 4 of 20 · Multiple Choice
A writer adapting the model text (T1) for a web page can turn one set of information into a table. Which set would gain the most from a table?
Answer: C
A table helps when readers must find and compare several numbers, and C collects the text's measurements and counts in one place. A and D are ideas that need the sentences around them to make sense, and B is a two-step sequence that a sentence already handles clearly.
Question 5 of 20 · Multiple Choice
For which part of the model text (T1) would a short animation help readers the most?
Answer: D
Paragraph 4 describes a change over time, fast flow followed by rapid thickening, which motion shows more clearly than words. A, B and C present a duration, a date and a list, which gain nothing from animation.
Question 6 of 20 · Multiple Choice
An engineering incident report on the flood will use headings. Which set would best serve engineers reading it?
Answer: A
A tells engineers what each section contains, in the order of a failure analysis: how the structure was built, what load it carried, how it failed, what followed and what should change. B names paragraph types, C uses playful titles that hide the content, and D numbers the parts without saying what is in them.
Question 7 of 20 · Multiple Choice
Which fact from the model text (T1) is most significant for explaining why the tank failed when it did, in January 1919?
Answer: B
The question is about timing, and B names the change in load that paragraph 3 connects to the failure. A concerns ownership and C the tank's purpose; neither explains the timing. D is a claim the auditor rejected, so it explains nothing about the cause.
Question 8 of 20 · Multiple Choice
The readers are students in a structural engineering course. Which addition to the model text (T1) would help them the most?
Answer: C
Engineering students want the material facts behind the failure, and brittleness explains why thin steel cracked rather than stretching. A honors the victims but does not serve this reader's purpose, and B and D are true but do not bear on why the structure failed.
Question 9 of 20 · Multiple Choice
Paragraph 4 of the model text (T1) begins, "Once the walls gave way, the molasses behaved in ways few people expect of a syrup." How does this opening link paragraph 4 to paragraph 3?
Answer: A
"Once the walls gave way" refers back to the failure that ends paragraph 3, and "once" marks the wave as what happened next and because of it. B misreads the sentence, which names no cause, C invents a contrast (the rescuers are not a subject of paragraph 4), and D reverses the text, which never doubts the failure.
Question 10 of 20 · Multiple Choice
Which revision combines these sentences so that the relationship between them is clearest? The tank leaked from the day it was filled. The company painted it brown.
Answer: C
C uses an opening phrase to show that painting was chosen instead of repair, which is the relationship that matters. A and B join the ideas as a simple addition, and D's "so then later" suggests only a loose sequence.
Question 11 of 20 · Multiple Choice
Why does the writer of the model text (T1) compare molasses to ketchup in paragraph 4?
Answer: B
The simile ties the syrup's behavior, flowing freely under a strong push, to a familiar experience, which manages a complex idea for general readers. A draws a practical conclusion the text never makes, C confuses a comparison of behavior with a claim about ingredients, and D ignores that the comparison explains how the wave moved so fast.
Question 12 of 20 · Multiple Choice
Which comparison would mislead readers about the molasses wave described in the model text (T1)?
Answer: D
Paragraph 4 says the syrup "cooled and thickened" and left victims trapped; it did not drain away, so D gets the most important feature wrong. A, B and C each match a feature of the text: great weight, fast flow followed by thickening, and trapping.
Question 13 of 20 · Multiple Choice
Which sentence conveys a knowledgeable stance about the cause of the tank's failure?
Answer: D
D states what the evidence supports and hedges only what cannot be known, as paragraph 3 of T1 does ("Later analyses have suggested"). A overclaims, B dismisses real evidence, and C sounds uncertain and personal rather than knowledgeable.
Question 14 of 20 · Multiple Choice
Which sentence best suits a museum panel for families with young children, rather than an engineering report?
Answer: B
B keeps the key fact and adds a comparison that a ten-year-old can picture. A, C and D are accurate, but their terms (liquid load, stress concentrations, thin-walled cylinder) suit engineering readers, not families.
Question 15 of 20 · Multiple Choice
Which sentence would best conclude a section on the auditor's finding (T1, paragraph 5)?
Answer: A
A follows from the paragraph: it states what the finding implied about cause and responsibility. B opens a new topic, C comments on the length of the case instead of its meaning, and D shifts to an opinion that the explanation does not support.
Question 16 of 20 · Short Answer
Rewrite these sentences from the weak draft (T2) as one or two sentences that show cause rather than sequence. Use a sentence structure other than "First ... Then" and add the facts from the model text (T1) that make the cause clear: "First the tank was built. Then it got warm."
Model answer: "Because the tank had been completed in 1915 without an adequate test, with walls about half as thick as its size required (T1, paragraph 2), it could not bear the added pressure when a warmed cargo arrived and the air turned mild in January 1919 (T1, paragraph 3)." Rubric line: 2 points for a structure that shows cause (a subordinate clause, a semicolon with a causal link, or similar), at least two accurate facts from T1 with citations, and no "then"; 1 point if the sentence still reads as a sequence or the facts are missing.
Question 17 of 20 · Short Answer
The model text (T1) mentions that Arthur Jell, who oversaw the tank's construction, "had no training in engineering or architecture." Explain in two or three sentences why this is a significant fact for the explanation, and name the later part of the text that it builds toward.
Model answer: The fact explains how a tank could be built with walls about half as thick as required and without an adequate test: no one qualified checked it (T1, paragraph 2). It builds toward the conclusion, which names "a structure that no qualified engineer checked" as one of the ordinary failures and notes that rules afterward required "oversight by licensed architects and engineers" (T1, paragraph 6). Rubric line: 2 points for explaining the fact's role in the chain and linking it to the conclusion with a citation; 1 point for one of these.
Question 18 of 20 · Short Answer
Write an analogy, one or two sentences long, that explains to general readers why molasses being "roughly 40 to 50 percent denser than water" (T1, paragraph 4) made the wave so destructive. Then write one sentence explaining where your analogy stops being accurate.
Model answer: "Being struck by the wave was less like being hit by a wave at the beach than by a wall of wet sand: for the same size and speed, a heavier fluid carries more force." Limit: "Wet sand does not flow like a liquid, and it does not thicken as it cools, so the analogy explains the weight of the wave but not the way it trapped people." Rubric line: 2 points for an analogy that explains the effect of density accurately and a limit that names a real difference; 1 point if the analogy is vague or the limit is missing.
Question 19 of 20 · Short Answer
Rewrite these sentences from the weak draft (T2) so that they are accurate and convey a knowledgeable stance, using the model text (T1): "Then the tank exploded because anarchists put a bomb in it. [...] 150 people died."
Model answer: "USIA claimed in court that anarchists had blown up the tank, but after about three years of hearings the court-appointed auditor rejected that claim and found the company responsible (T1, paragraph 5). The wave killed 21 people and injured about 150 more (T1, paragraph 1)." Rubric line: 2 points for correcting both errors (the rejected anarchist claim and the numbers), presenting the claim as USIA's rather than as fact, and citing T1; 1 point for correcting only one error.
Question 20 of 20 · Short Answer
The weak draft (T2) ends, "In conclusion, molasses is delicious but dangerous." Explain in one sentence why this fails as a conclusion, and write a concluding statement of two sentences that follows from the explanation and states its significance.
Model answer: The sentence does not follow from the explanation: it repeats a general idea about molasses instead of saying what the chain of causes means. Replacement: "The flood was not an act of nature but the result of decisions: a tank built without an adequate test and kept in use despite its leaks. Its lasting significance is the principle, later written into construction rules, that qualified engineers must check such structures before the public depends on them." Rubric line: 2 points for a clear reason and a conclusion that draws on the causes and states a significance or implication; 1 point for a conclusion that only summarizes; 0 for a new topic.
0 of 20 answered · 0 correct
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Frequently Asked Questions
10 Questions
What does WHST.11-12.2 mean?
WHST.11-12.2 means that students in grades 11 and 12 can write informative and explanatory texts in history, science and technical subjects, including the narration of historical events, scientific procedures and experiments, and technical processes.
Its five parts ask students to organize complex ideas so that each new element builds on the one before, with headings, graphics and multimedia where useful (a); develop the topic thoroughly with the most significant facts (b); link sections with varied transitions and sentence structures (c); use precise language and techniques such as metaphor, simile and analogy, with a knowledgeable stance (d); and write a conclusion that follows (e).
What does "each new element builds on that which precedes it" mean in WHST.11-12.2?
It means that every section of the text depends on the ones before it, so the reader could not understand it in a different order.
In the model text on this page, the section on the load only makes sense after the section on the tank's weakness, and the section on the wave only after the failure. A list of facts in any order does not meet this part of the standard.
How is WHST.11-12.2 different from WHST.9-10.2?
The grade 11-12 version asks for more complex organization, more selective development and a more knowledgeable voice.
Grade 9-10 asks students to make connections and distinctions and to develop the topic with sufficient facts; grade 11-12 asks that each element build on the one before and that students choose the most significant facts. Grade 11-12 also names metaphor, simile and analogy and asks for a knowledgeable stance, while the 9-10 standard has a separate part for formal style and objective tone.
Why does a history and technical writing standard mention metaphor and analogy?
Because a good comparison can make a complex mechanism clear to readers who lack the technical background.
On this page, for example, a comparison with the pressure a swimmer feels at the bottom of a pool explains why the tank's failure began near its base. A writer must also know where a comparison stops being accurate, and say so when readers might be misled.
What is a "knowledgeable stance"?
It is the voice of a writer who knows the subject well: confident about what is established, careful about what can only be inferred.
In practice, it means stating facts directly, attributing claims to their sources ("USIA argued"), and hedging inferences ("later analyses have suggested"). It also means choosing the terms and detail that suit the readers' expertise.
What is the difference between WHST.11-12.2 and W.11-12.2?
W.11-12.2 is the English-class standard for informative writing, while WHST.11-12.2 applies it to history, science and technical subjects.
The WHST version names the texts those courses write, such as the narration of historical events and technical processes, and it asks for a style that responds to the discipline and to the expertise of likely readers. Unlike W.11-12.2, it has no separate part for formal style and objective tone.
Why use the Boston Molasses Flood to teach explanatory writing?
Because it cannot be explained well as a list: its causes only make sense in order.
The event joins history (a company's decisions and a court case) with engineering and physics (an untested tank and a liquid that thickened as it cooled). That mix forces students to select the most significant facts, manage technical ideas for general readers and state a significance that goes beyond the strange story.
Do students need outside research for this lesson?
No: the model text and the research notes on the page supply the facts for every task.
Teachers who extend the lesson into a research project can have students compare published histories of the flood and note where their figures differ, which connects to WHST.11-12.7 and WHST.11-12.8.
How is WHST.11-12.2 usually assessed?
It is usually assessed through written explanations in the content class, scored with a rubric for organization, development, language and conclusion.
Common tasks include explanations of historical events, lab and engineering reports, and research papers. Check your state's released writing tasks and scoring guides for how they weigh organization and use of sources.
How can parents help with explanatory writing in history and science?
Ask your student to explain an event or a process in order, and to say why each step led to the next.
Useful questions are "What had to happen first?", "What changed that made this happen then?" and "What does this mean for us now?" These are the questions a good explanation answers.
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Related Standards
5 standards
These standards connect to WHST.11-12.2: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
WHST.9-10.2Prerequisite
Write informative texts that make connections and distinctions in a discipline
