On This Day: The Boston Molasses Disaster of 1919 "On January 15, 1919, in Boston's North End, a 50-foot-tall tank holding 2.3 million gallons of molasses burst, unleashing a deadly wave that rose nearly 25 feet high at one point. The destructive flood threw people and horses about, smashed buildings, and even damaged the steel supports of an elevated railway. Rescuers had to wade through knee-deep molasses and sticky debris to reach survivors. Twenty-one people died in the disaster, another 150 were injured, and the cleanup lasted for weeks. The cause of the failure was determined to be faulty construction and poor maintenance."