The Explainer General
The weather was one factor: unusually warm for winter.
Purity Distilling Company fermented and distilled molasses to make rum and alcohol. The 18th Amendment to the United States Constitution, prohibiting sales of alcoholic beverages, was due to be passed the very next day. This may have prompted Purity to collect as much molasses as possible.
The enormous tank holding the molasses was about 50 feet tall and 90 feet in diameter, holding 2,300,000 gallons. It was poorly built of thin steel painted brown to hide its leaks. Local families often collected some of the dripping molasses to sweeten their food. The unseasonably warm temperature quickly rose from 2° F (-16.7° C) to 40° F (4.4° C), expanding the liquid, and natural fermentation produced CO2 increasing tank pressure.
Just after noon, North End families felt the ground shake and heard a sound like a machine gun— the tank’s rivets popping out. The big tank exploded, sending a 25-foot wall of molasses roaring down the hill toward Commercial Street at about 35 miles an hour. In front of the molasses went a blast of air that blew some folks off their porches and tumbled others along the street like rag dolls. Homes and buildings were destroyed, smashed from their foundations. Horses pulling wagons were swept away. The steel girders of the Boston Elevated Railway were buckled, knocking a rail-car off the tracks.
Twenty-one people were killed and more than a hundred were injured. Many were saved by Massachusetts Maritime Academy cadets who rushed off their docked training vessel and plunged into the brown goo to rescue people. It’s difficult to know how many dogs, cats and horses died.
As you can imagine, the clean-up was awful. Firehoses from hydrants and harbor fireboats washed away as much as possible. Boston Harbor was brown for months. Sightseers tracked the goo back to homes, into hotels, onto pay-phones and onto doorknobs. Everything Bostonians touched was sticky for months.
Some say that on a hot summer day along the North End’s docks, the sickly sweet smell of molasses lingers. Bostonians can smile at the Great Molasses Flood now, but in January of 1919, that cascade of disasters was deadly serious.
In tomorrow's second Minute on climate change, Dorothy Hinshaw Patent will explain what is happening both practically and scientifically with global warming.