Boston, MA: 1.15.1919 – Cylinder Stress Failure – The Great Molasses Flood, also known as the Boston Molasses Disaster or the Great Boston Molasses Flood, occurred on January 15, 1919 in the North End neighborhood of Boston, Massachusetts. 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 entered local folklore and for decades afterwards residents claimed that on hot summer days the area still smelled of molasses. From Wikipedia, the free encyclopedia.

On January 15, 1919, Boston suffered one of history’s strangest disasters: a devastating flood of molasses. The “Great Molasses Flood” tore through the North End and deposited so much gooey residue that locals claimed they could still smell the molasses on warm days decades later. Let’s take a look at this odd, tragic story.
While most of us probably think of molasses as a tasty ingredient in treats like gingerbread, the sticky stuff has quite a few other uses. With a little know-how one can turn molasses into rum or industrial alcohol fairly easily, and the Purity Distilling Company had built the gigantic tank in Boston’s North End in 1915 to supply its booze-making operations. The steel tank was enormous: 50 feet tall, 90 feet across, and capable of holding 2.5 million gallons of molasses. (Although Prohibition kicked in with Nebraska’s ratification of the Eighteenth Amendment the very next day after the 1919 disaster, the United States Industrial Alcohol Company, Purity Distilling’s parent company, still had a license to distill alcohol for industrial applications.)
The massive tank was nearly full on January 15 thanks to a recent infusion of 2.3 million gallons of Puerto Rican molasses. Just after noon, something went horribly wrong. Witnesses later recalled hearing a noise like gunfire as the tank’s rivets popped and the steel sides ripped open. Suddenly, 26 million pounds of molasses were tearing down Commercial Street in a 15-foot wave.
A giant wave of a sticky foodstuff sounds like something from a cartoon, but the surging molasses was a shockingly destructive force. The wave moved at upwards of 35 miles per hour, and the power was sufficient to rip buildings off of their foundations. The molasses snapped the support girders from an elevated train track and smashed multiple houses.

The disaster occurred at the Purity Distilling Company facility on January 15, 1919. The temperature had risen above 40 °F (4 °C), climbing rapidly from the frigid temperatures of the preceding days.

Molasses can be fermented to produce rum and ethanol, the active ingredient in other alcoholic beverages and a key component in the manufacturing of munitions.[2]:11 The stored molasses was awaiting transfer to the Purity plant situated between Willow Street and what is now named Evereteze Way, in Cambridge.


 Modern downtown Boston with molasses flood area circled.

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 variously reported that as it collapsed they felt the ground shake and heard a roar, a long rumble similar to the passing of an elevated train (coincidentally, with a line of that type close by), a tremendous crashing, a deep growling, or “a thunderclap-like bang!” [emphasis added], and as the rivets shot out of the tank, a machine gun-like sound.

The collapse unleashed a wave of molasses 25 ft (8 m) high at its peak, moving at 35 mph (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 ft (60 to 90 cm). Puleo quotes a Boston Post report:

Molasses, waist deep, covered the street and swirled and bubbled about the wreckage … Here and there struggled a form‍—‌whether it was animal or human being was impossible to tell. Only an upheaval, a thrashing about in the sticky mass, showed where any life was … Horses died like so many flies on sticky fly-paper. The more they struggled, the deeper in the mess they were ensnared. Human beings‍—‌men and women‍—‌suffered likewise.

 Damage to the Boston Elevated Railway caused by the flood. The Boston  …