On January 15, 1919, more than 2 million gallons of molasses spewed through Boston’s North End in an event known today as the Great Molasses Flood. The incident occurred due to a faulty storage tank managed by United States Industrial Alcohol, a distilling company. The massive storage vat measured 50 feet high with a diameter of 90 feet, and was known to rumble and leak from the time it was built in 1915. These issues occurred in part because the walls were only 0.31 to 0.67 inches thick, far too thin to contain the weight of a full tank of molasses.
On January 12 and 13, 600,000 gallons of molasses were pumped into the tank, filling it to capacity. This, coupled with temperature fluctuations that affected both the molasses and the vat itself, put an added strain on the tank. Two days later, the container burst from the pressure, sending a 40-foot-high wave of molasses gushing through the streets at a speed of up to 35 miles per hour. The destructive force of gooey liquid destroyed buildings and claimed 21 lives, requiring 87,000 worker hours to clean up in the event’s aftermath. For years after, residents claimed the area reeked of molasses on warmer days.