The Great Molasses Flood: The History of the Unusual Disaster that Struck Boston in 1919

The morning of January 15, 1919, came warm and bright to the North End of Boston. The temperature had climbed nearly 40 degrees in two days, an unusual mercy after a brutal cold snap. Children played in the streets between tenement walls, workers at the public works department gathered for their noon meal in the yard behind their building, and firefighters tended their station at Engine 31 on Commercial Street, their pumper truck washed and waiting. A trainload of passengers rumbled along the Atlantic Avenue Elevated, the iron tracks running parallel to the waterfront. Somewhere on the wharves, men loaded freight onto wagons. Elsewhere in a nearby tenement, an Italian widow prepared dinner. Another old woman was setting out laundry to dry.

Then, at 12:30 in the afternoon, the great steel tank at 529 Commercial Street tore itself apart while it was holding 2.3 million gallons of molasses. The tank stood 50 feet high and 90 feet across after it had been built in about two months during the autumn of 1915. It was never properly tested, never adequately inspected, and never trusted by the men who worked beside it. When its plates failed, the molasses rushed out as an enormous wave that witnesses later described as being 25 feet tall and 160 feet wide, and as if that wasn’t enough, the wave moved at an estimated 35 miles per hour. The molasses carried with it the tank's steel rivets, fragments of iron plating, and a tremor through the ground that rattled windows blocks away. When it struck the Engine 31 firehouse, it lifted the building off its foundation, and when it struck the Clougherty home, the molasses pushed the house against the iron supports of the elevated railway, snapping one of the railway’s supports clean in half and lifting a railway car off its tracks. The wave even swept horses, wagons, men, women, and children into the harbor.

By the time the wave finally settled, 21 people lay dead, and 150 more required hospital care.