There were many quirky events in history, but of all the events in modern US history, this is one of the quirkiest.

Imagine a wall of molasses two stories high bearing down on an urban neighborhood. It helps to understand some history behind why molasses was so important then. Back during the slave trade, molasses was shipped up from the Caribbean to be made into rum, and the rum was shipped to Africa to be traded for slaves, and the slaves were shipped to the Caribbean to be traded for more molasses.

After slavery, molasses continued to be used as a sweetener until refined sugar became cheaper to make. The company that owned the tank that burst made industrial alcohol, which was used for explosives. There was considerable demand for explosives during World War I, and to meet it, a bigger tank was erected that towered 50 feet high in Boston’s North End. Ninety feet in diameter, it was considered by many to be a blight on the neighborhood, which consisted largely of Italian immigrants who held little political clout.

Built during tight timelines, people worried about the tank, which oozed molasses constantly and made weird noises. Everyone was reassured that all was in order, and there was nothing to worry about. One cost-saving “fix” was to paint the tank brown, so that the molasses would not show up as readily.

As the country demobilized, the US Industrial Alcohol Company thought they could cash in on the pre-Prohibition rush for alcoholic beverages. This meant filling the tank to its two million gallon capacity.

The tank failed, sending a wave of molasses through the neighborhood at 35 miles per hour. In addition to the wave, pieces of the tank itself formed projectiles, damaging the Atlantic Avenue El. Wood frame buildings were shattered, and people and horses were mired in the thickening molasses. Some 20 people were killed, and over 100 were injured. For years afterward, the smell of molasses lingered in the neighborhood.

US Industrial Alcohol Company maintained that the tank was sabotaged by anarchists. Testimony during the inquest, however, seemed to point to the use of substandard building materials.

The book itself is an interesting read about this period of Boston history, and is the only book devoted to the subject.

Puleo, Stephen. 2003. Dark Tide : The Great Boston Molasses Flood of 1919. Boston, Mass: Beacon Press.