Weird History: The Great Molasses Flood

The following story sounds made up. I could not believe it the first time I heard about it. But rest assured, it is completely true. In 1919, Boston experienced a tragic flood. But the liquid flowing through the streets was not water. It was molasses. You heard that right. Molasses. This may sound funny, but the truth is it was tragic. In the end, the flood killed 21, injured 150, and destroyed countless homes, businesses, and even trains.

Molasses, aside from being a sweetener, can be used to make ethanol, the active ingredient in alcohol. Needless to say, it was an important product to keeping the public happy, especially in Boston. The Purity Distilling Company was located in Boston’s North End. Their massive tank was 50 feet tall and 90 feet in diameter. Inside sat 2.3 million gallons of molasses.

January 15, 1919 offered a warmer reprieve from the brutal winter days that proceeded it. A freshly delivered batch of molasses, warmed slightly, mixed with the older, colder molasses already in the tank. Soon after, just past noon, the tank burst, sending those 2.3 million gallons of the sticky stuff through the streets.

Ever hear the phrase “slow as molasses?” Turns out it’s not true. The molasses flowed through the streets at speeds upwards of 35 miles per hour. The North End is a hilly neighborhood, which did not help problem. Molasses is 40 percent denser than water. This means that it has much more potential energy. When unleashed, it becomes a scary situation. The flowing molasses formed a wave that stood 25 feet at its peak. Residents said they felt the ground shake. They described the noise as a thunder bang or like the noise of a passing train. It was so strong that it tipped a passing streetcar off of its tracks. The air around the sugar rush lifted people up, trashing them around. It sent debris flying, hitting those in its path. It even forced a truck into Boston Harbor.

As time went on, the molasses became thicker as it was exposed to the cold air. People became trapped in it, as if it were quicksand in a cartoon. This made rescuing those in its path even more difficult. Over 116 cadets from the nearby USS Nantucket ran to enter the knee-deep molasses, pulling out survivors. Red Cross nurses tended to the injured and even dived into the mess, risking their lives to help those trapped. Boston Police, the Army, the Navy, and the Red Cross worked throughout the night, setting up a makeshift hospital in a nearby market. It was so hard to move through the molasses that search efforts went on for four days. Several killed were so covered that it was hard to recognized them. Others had been swept into the harbor and went undiscovered for months.

Cleanup took weeks. Crews used saltwater to wash the molasses and then sand to absorb it. Boston Harbor was stained brown until the summer. The whole city was covered in molasses. Rescue and cleanup workers, as well as curious residents, would track molasses from the spill site all over the city: on the train, in the streets, and into their homes. One person said, “Everything that a Bostonian touched was sticky.”