On January 15, 1919, people in Boston’s North End were startled by a loud rumbling noise. They watched in horror as a five-story tank broke apart, unleashing a wave of molasses 15 feet high and 160 feet wide.
Moving at 35 miles per hour, it traveled over two blocks and engulfed everything in its path. The disaster killed 21 people, injured 150, and caused property damage of more than $100,000,000 in today’s dollars. The tank’s owners claimed that anarchists had dynamited it as a protest against the American government. In fact, the tank had been hastily constructed and overloaded.
Years later, the tank’s owner was found liable and was ordered to pay compensation to the victims.
Sources
Historic Ipswich 
Probably the only good thing is that it happened in January; otherwise, can you imagine the fly problem?