The molasses disaster killed 21 people, including 17 workers, and injured 150. Witnesses said the rivets popping out of the tank sounded like machine gun fire.
The tank, 50 feet high and 90 feet in diameter, contained 2.3 million gallons of molasses originally destined for use in a munitions plant. The deadly ooze damaged the Boston Elevated Railway on Atlantic Avenue. It then tipped over a rail car and knocked buildings off their foundations. The molasses surge picked up a truck and threw it into Boston Harbor.
Inside the Boston and Worcester freight terminal, the river of molasses poured through the doors and windows. It killed workers like trapped animals.
Outside, the wall of goo trapped some unlucky victims, hurled some into the air, flung some against freight cars and smothered still others.
The molasses was waist deep in the streets, and covered struggling forms trying to escape the sticky mass. It was hard to tell if they were men, women, children or horses. The more they struggled, the more ensnared they became.
Over a hundred cadets from the training ship USS Nantucket, docked nearby, ran to the scene to rescue victims and keep onlookers away from danger. The police and Red Cross arrived and set up a makeshift hospital in a nearby building. Rescuers spent the next four days searching for victims.
News of the Molasses Disaster
The Boston Evening Globe reported the boiling sludge buried scores of people inside ruined buildings, killing some and badly injuring others.
Fragments of the great tank were thrown into the air, buildings in the neighborhood began to crumple up as though the underpinnings had been pulled away from under them...
The explosion came without the slightest warning. The workmen were at their noontime meal, some eating in the building or just outside, and many of the men in the Department of Public Works Buildings and stables, which are close by, and where many were injured badly, were away at lunch.
The Globe reported no one had a chance to escape once they hear the low, rumbling sound. Buildings seemed to crinkle as though made of pasteboard.
In the aftermath, local residents filed a class-action suit against the company, Purity Distilling Company. Purity claimed anarchists blew up the tank, but investigators found it was poorly constructed and never tested for safety. When filled, it leaked molasses, and the company painted it brown to hide the leaks.
What Caused It?
Nearly 100 years later, a new study found the cause of the molasses disaster to be steel too thin and brittle to withstand the pressure of 2.3 million gallons of molasses. Ronald Mayville, a structural and metallurgical engineer, wrote in Civil and Structural Engineer Magazine that the steel was 50 percent too thin. Engineers should have known that in 1919, he wrote.
For many years, North End residents said they smelled molasses on hot summer days.
And in 2016, Harvard University scientists concluded the molasses disaster would have killed fewer people had it happened in the summer. They figured the winter air cooled and thickened the goo, making it harder to rescue victims.
This story about the Boston molasses disaster was updated in 2018.