The great molasses flood of 1919 stopped Boston in its tracks.
This past December, a town in Germany made international headlines when a local chocolate factory’s storage tank ruptured, literally repaving the streets with a layer of chocolatey goo so thick it took 25 firefighters armed with shovels, blowtorches, and hot water to chip it all away.
The story was a funny little curio, to be sure. But for fans of weird history, it also couldn’t help but bring to mind one of the oddest and most infamous events of food-related disaster on record: the Great Molasses Flood of 1919. And since I haven’t covered it in these pages yet—and also because it just celebrated (if that’s the right word, which it isn’t) its centenary in January—now feels like as good a time as any to dive back in and get reacquainted.
The date is January 15, 1919. The scene: the North End neighborhood in Boston. There, by the harbor, sits a massive, 90-foot-wide tank capable of holding more than two million gallons of molasses, which at the time was being imported from the Caribbean to be distilled into rum and ethanol. But this was no ordinary molasses tank. No, this tank was an incredibly shoddy molasses tank. It was built a few years earlier for the nearby Purity Distilling Company, but for some reason was never properly tested, and problems were evident early on. For one, the tank had a leak so bad that local kids figured out they could bring over empty cans and scoop up the dregs for free. When notified of this issue, the project manager responded by having the tank painted a molasses-y shade of brown, so that the leaks would be harder to see.
On that fateful January afternoon, the gigantic tank, full nearly to the brim after a recent deposit, split open for good.
“A dull, muffled roar gave but an instant’s warning before the top of the tank was blown in the air,” wrote the New York Times the following day. And the ensuing wave of molasses that flooded the streets of Boston was nothing short of surreal. Eyewitnesses estimated the wave was between 8 and 15 feet high, and it moved at 35 miles per hour—in every direction. In a matter of seconds, two full city blocks were submerged.
The explosion devastated the surrounding area. The gooey wave moved so quickly it caught bystanders before they were able to get to higher ground. Even when the molasses leveled off at about knee height, cooling in the winter temperatures, it was still so sticky that people couldn’t escape easily.
“Here and there struggled a form,” wrote the Boston Globe, “whether it was animal or human being was impossible to tell.” Meanwhile, the force of the explosion itself toppled several buildings and destroyed a chunk of an elevated rail line shortly after the train had passed over it. In all, 21 people were killed, and another 150 were seriously injured. The last victim wasn’t found for more than 10 days.
After an inquiry that lasted three years, an auditor found that the tank wasn’t built to construction standards, and for a long time, it was assumed that the rivets were to blame, in conjunction with a dangerous buildup of carbon dioxide inside the tank. More recently, however, a local engineer, who studies the flood as a hobby, found the type of steel used in the tank was, in fact, the main culprit.
While not considered a risk at the time, engineers now know that this kind of steel is too brittle, and therefore more likely to crack under duress. In this case, the steel was also only half as thick as it should have been, given how much liquid the tank was meant to hold. This same steel was also used in the construction of the Titanic, which is not generally a comparison anyone wants to be part of.
Following the inquiry, the company that owned the tank, U.S. Industrial Alcohol, was forced to pay $600,000 (roughly $6.5 million by today’s standards) in settlements. Cleanup in the surrounding blocks took weeks, and far longer in all of the outlying areas and corners to which the molasses ultimately spread. And once the streets were officially scrubbed clean of the deadly, sticky mess, reports persisted of the smell of molasses in central Boston for decades afterwards.
