The U.S. city that experienced the Great Molasses Flood of 1919 was Boston.
The disaster struck Boston’s North End on January 15, 1919, when a huge storage tank belonging to the Purity Distilling Company burst near the waterfront. The tank held as much as 2.3 million U.S. gallons of molasses, which rushed through nearby streets in a dense wave.
The flood killed 21 people, injured about 150, and damaged buildings, vehicles, railway infrastructure, and nearby homes. Molasses can behave as a shear-thinning, non-Newtonian fluid: it may flow rapidly under stress but become extremely thick as it cools. That combination made the wave both destructive and difficult for rescuers to navigate.
The company initially suggested sabotage, but a long legal case found the United States Industrial Alcohol Company responsible. The disaster helped encourage stricter oversight of industrial construction, including greater involvement by qualified engineers. Philadelphia, Chicago, and New York had major industrial accidents too, but none was the Great Molasses Flood.