The Great Molasses Flood

On the date in 1919 a wave of molasses washed through the streets of the North End of Boston. There's actually a book about it and I met the author, Stephen Puleo, once at a Bostonian Society event. The picture above is from the Bostonian Society Archives. The puddle is molasses.

This summary is from Mass Moments.

...in 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 ordered to pay compensation to the victims.

When I was a little girl, on really hot days, people used to swear you could still smell it.