It was an unseasonably warm day in Boston on January 15th, 1919. Being a Wednesday, the industrial heavy North End was buzzing with the normal sights and sounds of early 20th century commerce. Because it was so warm, spirits were high on the streets. Just two days previous, the temperature had been just above zero. Many had an extra skip in their step and held optimism’s flame for an early spring.
But trouble was brewing above 529 Commercial Street in the form of a 50 foot high cast iron tank filled with 2.5 million gallons of crude molasses. At about 12:40 PM, the tank began to rupture with a loud rumble. Sounds of multiple pops and cracks, described by some witness like that of a machine gun, were heard as rivets shot free of the tank. The ground shook as if a train were passing by.
As the tank collapsed, an immense wave molasses 15 feet high and moving as fast as 35 miles an hour flooded the surrounding streets. The wave had sufficient force to crush the girders of a nearby elevated railway track, plunging a train car off the track and onto the street below. Nearby buildings were swept off their foundations and crushed. Caught unawares, 22 people were killed and 150 were injured by the river of sweet-smelling, sticky molasses.
Purity Distilling, who owned the tank, quickly blamed sabotage minded anarchists for the disaster. However, the subsequent investigation ruled that the tank failed due to faulty maintenance and an abnormal buildup of carbon dioxide pressure caused by the significant swing in temperature over the preceding days.
It took two weeks and over 87,000 work hours to remove the molasses from the affected cobblestone streets, theaters, businesses, automobiles and homes. The nearby harbor was still brown with molasses until summer.
Old-timers still claim that on hot summer days a faint, sickly sweet odor wafts up from streets of the North End — the stench of ancient molasses.