The Boston Molasses Disaster occurred on January 15, 1919, in the North End neighborhood of Boston, Massachusetts in the United States. A large molasses storage tank burst, and a wave of molasses rushed through the streets at an estimated 35 mph (56 km/h), killing 21 and injuring 150. The event has entered local folklore, and for many decades residents claimed that on hot summer days, the area still smelled of molasses.
At about 12:30 in the afternoon near Keany Square, at 529 Commercial Street, a molasses tank 50 ft (15 m) tall, 90 ft (27 m) in diameter and containing as much as 2,300,000 US gal (8,700 m3) collapsed. Witnesses stated that as it collapsed, there was a loud rumbling sound, like a machine gun as the rivets shot out of the tank, and that the ground shook as if a train were passing by.
The collapse unleashed a wave of molasses 25 feet (7.6 m) high at its peak, moving at 35 miles per hour (56 km/h). The molasses wave was of sufficient force to damage the girders of the adjacent Boston Elevated Railway's Atlantic Avenue structure and tip a railroad car momentarily off the tracks. Author Stephen Puleo describes how nearby buildings were swept off their foundations and crushed. Several blocks were flooded to a depth of 2 to 3 feet (60 to 90 cm).
Out of all the numbers, I am going to go with 2,300,000 the estimated number of gallons of molasses,