On the afternoon of the 15th, the tank finally split wide open, unleashing 2,300,000 gallons of molasses on Boston’s North End. Despite the expression “slow as molasses in January”, this molasses came at the speed of a freight train. A 30-ft-high “tidal wave”, weighing 13,000 tons, headed straight for the surrounding buildings. The effects were devastating. Molasses smashed houses and industrial buildings into splinters, trapped or buried everyone in its path, and piled cars and freight trains on top of each other. It surged into neighboring multi-story apartments, filling the cellars, and swept them right off their foundations. The fire station wildly rode the molasses wave all the way to Boston Harbor’s edge. Twenty-one people died, 150 were injured, and countless horses either died or had to be put down. The molasses flood ultimately caused about $100 million worth of damage.
By the time rescuers rushed to the scene, the molasses had formed into a thick lake three feet deep and hundreds of feet wide. The rescue and cleanup took weeks, even with thousands of men working around the clock. Since regular water wouldn’t work, seawater from Boston Harbor was pumped in to wash the gobs of goo from every imaginable surface. The molasses mess turned Boston Harbor brown for a long time.
After the disaster, a suit was brought against USIA, the company that had built the tank which was so terribly put together that it was a wonder it had held up at all. Instead of fixing it, the company had painted it brown to hide the leaking molasses. The company’s claim that Communist sympathizers had sabotaged the tank didn’t fly, and after years of court fights, it was made to pay damages to the city and the victims' families. The result of this tragedy was that construction standards were tightened and enforced to ensure that a flood of molasses would never engulf a city like Boston again.