Illuminating History's Most Obscure Corners | Issue #34 | May 2026
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On the morning of January 15, 1919, the children of Boston's North End were doing what they always did at lunchtime near the molasses tank on Commercial Street.
They were licking the ground.
The tank leaked so reliably, so generously, that the Italian and Irish immigrant families of the neighborhood had come to think of it as a permanent amenity — a fifty-foot steel fixture that wept sweetness onto the pavement and asked nothing in return. Children brought cups. Mothers sent them.
At 12:40 that afternoon, the tank stopped leaking.
It did this by exploding.
Molasses is what you get when you refine sugarcane — the dark, thick syrup left over after the sugar crystals have been extracted. For most of human history it was simply a sweetener, cheaper than sugar and considerably less glamorous. It went into gingerbread, rum, and the cooking of people who couldn't afford anything better.
Then someone discovered it could be fermented into industrial alcohol.
Industrial alcohol, in the early twentieth century, was the unglamorous backbone of modern warfare. It went into dynamite, smokeless powder, and artillery shells — things that armies needed in quantities that would have been unimaginable a generation earlier. When the First World War began in 1914 and American munitions companies started fulfilling contracts for Britain and France, the demand for molasses went through the roof.
The United States Industrial Alcohol Company — USIA — needed somewhere to store vast quantities of molasses arriving by ship from Cuba and the Caribbean, to be fermented at their distillery in Cambridge and turned into the alcohol that would eventually become explosives. They needed a tank. A very large tank. And they needed it fast.
They chose Boston's North End.
The North End was a working-class immigrant neighborhood — densely packed, politically powerless, and conveniently located on the waterfront near the railway lines. The residents were not consulted. Many weren't citizens and couldn't have objected even if anyone had thought to ask.
No permit was required. The tank was classified, legally, as a receptacle.
Construction began in December 1915, which left approximately six weeks to build a steel tank fifty feet tall and ninety feet in diameter, capable of holding 2.3 million gallons of liquid. The man put in charge was Arthur Jell, USIA's treasurer. He had no engineering experience. He could not read blueprints. He had been told his career depended on finishing before the end of the year.
He finished it in time.
To test whether the tank was watertight, Jell filled it with six inches of water — roughly enough to test a birdbath — and declared it structurally sound. The molasses arrived on December 31st. By January 1st, it was bleeding through the rivets.
Jell had it recaulked. It kept leaking. He had it recaulked again. It kept leaking. Eventually, in a move that said everything about his priorities, he had the steel-colored tank painted brown, so that the seeping molasses would be harder to see against the sides.
The tank continued to leak. The children continued to collect it in cups. The tank also groaned — a long, low metallic groan every time it was filled, that residents heard from their apartments and got used to, the way you get used to any sound that has never yet killed anyone.
A USIA employee named Isaac Gonzales did not get used to it.
Gonzales was assigned to oversee the molasses transfers from the Cuban steamers. From his first day on the job, he reported the leaks to his superiors. He was told not to worry. He worried anyway — so badly that he began having nightmares, started checking on the tank in the middle of the night, and on some nights simply slept beside it, listening.
Eventually, he ripped shards of cracking steel from the tank's walls, carried them into Arthur Jell's office, and put them on the desk.
Jell looked at the shards. He looked at Gonzales.
"I don't know what you want me to do," he said. "The tank still stands."
Gonzales quit. A few months later, the tank proved him right.
By January 1919, the war was over. But molasses was still in high demand — now for a different reason. Prohibition was coming. The Eighteenth Amendment was about to be ratified, and it would take effect a year later. USIA was racing to convert as much molasses into rum as possible before the window closed. Two days before the disaster, a ship arrived from Cuba carrying a fresh load of warm molasses. The tank was filled to near capacity.
The warm molasses settled on top of the cold molasses already inside. The pressure built.
At 12:40 p.m. on January 15th, with a sound witnesses described as machine-gun fire — rivets popping in sequence — the tank burst open.
The wave was twenty-five feet high and moved at thirty-five miles per hour. Molasses is forty percent denser than water. It hit the neighborhood with the force of something that had no business moving that fast. Buildings crumpled. The elevated railway structure buckled and collapsed. A freight car was lifted off the tracks. The firemen at Engine 31, who had been eating lunch and playing cards, were buried where they sat.
Then the molasses began to cool.
Harvard engineers who studied the disaster nearly a century later found that this was what made it so deadly. The wave moved fast, then slowed as it cooled to Boston's January temperatures and thickened around its victims. People who might have been pulled free were held in place as it hardened. Some suffocated. Others drowned. The horses working the waterfront died the way the Boston Post described it, with a reporter's bleak economy: like flies on sticky flypaper.
Twenty-one people died. A hundred and fifty were injured. One victim, a wagon driver named Cesare Nicolo, was not found for nearly four months — eventually recovered from Boston Harbor, where the molasses had carried him.
The cleanup took 87,000 worker-hours. Boston Harbor ran brown until summer. The streets of the North End smelled of molasses on hot days for years afterward. Some say decades.
Boston Molasses Flood Aftermath with Tank Size and Approximate Location Superimposed. Jacione, CC BY-SA 4.0
USIA's response to having killed twenty-one people was to blame Italian anarchists.
This was not as absurd as it sounds, which is a depressing thing to have to say. It was 1919 — the year anarchist cells mailed bombs to forty prominent Americans, blew up the Attorney General's front porch, and gave J. Edgar Hoover, then a young Justice Department operative, the pretext he needed to raid immigrant communities across the country without warrants. Italian was, in that particular moment, a synonym for suspect. USIA spent over $50,000 on expert witnesses trying to make the theory stick.
The trouble was that everyone already knew the tank was failing. The children with their cups knew it. Gonzales knew it. The steel shards on Arthur Jell's desk knew it. Over the course of nearly six years of legal proceedings — 3,000 witnesses, 45,000 pages of testimony, so many lawyers the courtroom couldn't hold them all — the evidence was not kind to USIA's theory.
In April 1925, the court ruled that the tank had failed due to structural negligence. USIA paid $628,000 in damages. The families of the dead received approximately $7,000 each.
It was the first successful class action lawsuit in American history.
It was also, eventually, the reason that buildings require permits, that engineers must sign off on structural calculations, that tanks must be tested before use. Every construction regulation that currently exists in the United States has a grandmother, and her name is the Boston Molasses Flood. Before January 15, 1919, a company could build a fifty-foot steel tank next to a residential neighborhood, fill it with 2.3 million gallons of dense liquid, ignore four years of warnings, paint it brown to hide the evidence, and face no regulatory consequence whatsoever.
Nobody had thought to make any of that illegal. The tank was a receptacle.
The concrete base of the tank is still there, twenty inches below the surface of a baseball diamond at Langone Park in the North End. Children play on it on summer afternoons, which seems about right.
Arthur Jell was never personally charged with anything. USIA did not rebuild the tank. New technology had made molasses distillation obsolete, and Prohibition had taken care of the rum.
Isaac Gonzales — the man who slept next to the tank, brought the shards to the office, quit in despair, and was vindicated by two million gallons of physics — does not appear in most accounts of what happened. There is no record of where he went, what he thought when he heard the news, or whether anyone from the company ever said a word to him.
The tank still stands, they told him.
Until it didn't.
Further Reading:
Puleo, Stephen. Dark Tide: The Great Boston Molasses Flood of 1919. Beacon Press, 2003. The definitive account — rigorously researched, reads like a novel. Start here. Puleo drew on the forty-volume transcript of Dorr v. United States Industrial Alcohol and interviewed descendants of victims and survivors.
Kops, Deborah. The Great Molasses Flood: Boston, 1919. Charlesbridge, 2012. A shorter, more accessible account that draws directly from the trial transcript. Useful companion to Puleo for readers who want the legal proceedings in detail.
Dorr v. United States Industrial Alcohol Company. Suffolk County Superior Court, 1925. The trial transcript runs to forty volumes and is held at the Massachusetts State Archives. Portions are quoted in both Puleo and Kops.
Sahn, Nicole, et al. "Fluid Dynamics of the 1919 Boston Molasses Flood." AIP Physics Today, 2017. The Harvard study that reconstructed the physics of the wave — how it moved fast, then slowed, then trapped its victims. Available at the American Institute of Physics.
Avrich, Paul. Sacco and Vanzetti: The Anarchist Background. Princeton University Press, 1991. Essential context for understanding why the Italian anarchist defense was plausible in 1919 and what it cost the North End community.
Boston.gov. "100 Years Ago Today: Molasses Crashes Through Boston's North End." January 15, 2019. boston.gov/news/100-years-ago-today-molasses-crashes-through-bostons-north-end. A concise official account with archival photographs.
What's Next in Obscurarium?
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