The Boston Molasses Flood of 1919 gave us modern building standards

This past weekend was the 103rd anniversary of the January 15, 1919 Boston Molasses Flood.

A lot of people chuckle at the notion, but it was a very big deal:

On Jan. 15, 1919, a tank of molasses burst, releasing a thick, sugary tsunami down the streets of Boston’s North End. This “Great Molasses Flood” killed 21 people, injured 150, and had effects far beyond the Boston waterfront.

Walking around the North End today, Stephen Puleo, author of Dark Tide: The Great Boston Molasses Flood of 1919, points to a plaque where the 50-foot-tall steel tank once stood. Baseball fields now line Boston Harbor, but Puleo says a hundred years ago, you’d find a bustling port, a municipal yard and an elevated railway. 

“This was one of the busiest commercial sites in all of Boston,” he explains. “Almost all of the shipping that left Boston to go up and down the East Coast, to go to Europe, left from this site. So there were deliveries all day long, this was a bustling, hustling kind of place.”

The tank was used to store molasses, which came up on ships from the Caribbean, until it could be transported to a nearby distillery where it was expected to become rum in the last days before Prohibition. Though only a few years old at the time of the flood, the tank showed signs of instability.

The tank leaked from the moment it was erected and it’s worth remembering this was a big tank. Most grain silos midwesterners are familiar with are about 30 feet tall (though can be much taller).

Why’d the tank fail? Because it was hastily built by unskilled laborers and, of all things, prohibition was coming.

Molasses has all sorts of uses, including as an ingredient in alcohol. Molasses was also used in WWI as a sort of sticky Molotov cocktail bomb.

After the war, bombs weren’t necessary so the company that owned the tank, U.S. Industrial Alcohol, pivoted back to alcohol. The problem, though, was prohibition’s sales deadline was approaching.

In that great American tradition, people rushed out to buy as much alcohol while it was still legal. To meet the increased demand, USIA rushed as much as they could out the door. One of the corners they cut was on this leaky tank that probably would have been fine if they hadn’t been working under their usual level of demand. But they were topping the thing off with as much molasses as they could store.

When a police officer who walked by one day and heard the pings and pops that initially sounded like gunfire, he took cover until he realized it was the metal rivets exploding out the side of the tank. He radioed to his headquarters immediately requesting “all available rescue personnel”. He knew what was coming.

When the tank gave way a few minutes later, it immediately demolished a nearby fire house and everything in its path. The initial wave was 20-30 feet high.

Rescuers worked for days to free people trapped in their homes, businesses, and basements.

For months the City of Boston tried all sorts of ways to remove the sticky mess, including lighting it on fire. But because it wasn’t hard like candy, it was just sort of a sticky blob that refused to budge. Eventually, as a last ditch idea a fireman had the notion to spray salt water from Boston Harbor on it, which did the trick to loosen it up and hose it into the bay. Not surprisingly, the oceanfront was brown for months.

After the disaster disabled one of the country’s busiest import and export hubs, the City of Boston established the first building codes in the U.S. and the first requirements for engineers and architects to sign their building plans. This also led to licensure of building trades professions.

So the next time you get miffed waiting on a city inspector to come sign off on your hastily-built garage or patio and wonder why that’s even necessary, it’s because you could be storing 2.2 million gallons of molasses that cold give way at any moment.

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Justin has been around the Internet long enough to remember when people started saying “content is king”.

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You’ll probably see him around Indianapolis on a bicycle.

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