The Great Molasses Flood, also known as the Boston Molasses Disaster and the Great Boston Molasses Tragedy, was a massive accident that happened in Boston, Massachusetts, in 1919, when a large molasses storage tank collapsed. Several people were killed or injured, and the damage was estimated to be in the millions by today's standards. The Great Molasses Flood signaled the beginning of an era in U.S. history when businesses would be held accountable for causing public harm as a result of their activities.
The event occurred on 15 January 1919 at the Purity Distilling Company facility located at Boston’s North End neighborhood. The chemical firm specialized in turning molasses, which was a standard sweetener at the time, into rum and ethyl alcohol using the distillation process. A five-story, 50-feet (15-centimeter) brown metal tank awaiting transfer to a nearby Purity plant burst, simulating machine-gun sounds as its rivets flew way and unleashing a wave of 2.3 million gallons (8.7 million liters) of molasses into the street. The collapse was so severe that the ground trembled. The wave traveled at 35 miles (56 kilometers) per hour, was as high as 15 feet (4.57 meters) and covered a 160-feet (48.77-meter) width.
Buildings were uprooted from their foundations and crushed by the sheer force of the molasses wave, which was recorded at 2 tons per square feet (200 kilopascals). Twenty-one people, mostly Irish and Italian laborers, were killed, crushed or drowned by the wave and rendered almost unrecognizable due to the sweetener glaze. Additionally, 150 people were injured, and several horses lost their lives.
Alcoholic distiller United States Industrial Alcohol Company (USIA), which was the tank’s owner, as well as parent corporation of the Purity Distilling Company, blamed the Great Molasses Flood on anonymous anarchists as the culprits who exploded the tank. This theory, however, was never substantiated. The families of the victims noted that the tank had been overloaded as far back as 1915, although USIA did nothing to address the problem.
The affected poor and working-class people of Boston’s North End filed a class-action suit against USIA, then one of the country’s most powerful companies, in the aftermath of the Great Molasses Flood. After five years, the Massachusetts Superior Court determined that the collapse of the tank was due to its structural deficiencies, not an act of sabotage. The USIA eventually paid $600,000 US Dollars—the equivalent of almost $7 million USD in 2011—to the victims of the Great Molasses Flood.