Swept Away by Syrup!

In 1915, U.S. weapons makers were preparing for the possibility of the country entering World War I. They needed to increase the number of weapons they made. That meant they needed more molasses. Why? At the time, this sugary syrup was used to make bombs. The company that processed molasses for weapons wanted to store the sticky goo near Boston Harbor. But the company’s sloppy solution would soon cause an epic disaster in the city.

Boston’s North End, 1915: The U.S. Industrial Alcohol Company builds a five-story tank, designed by a manager with no engineering training.

Come on, let’s rivet this next steel sheet.

The company sure wants this done in a hurry!

From the start, gooey molasses leaks from cracks in the tank.

LOOK! Free molasses!

Yum, this stuff tastes great!

The company paints the tank brown—the color of molasses—to try to hide the leaks.

January 14, 1919: Workers pump a new shipment of molasses through an underground pipe into the 2.3-million-gallon tank. The tank groans loudly as it’s filled.

Keep it coming!

Think that tank’s gonna hold?

Let’s hope so.

Four days later: At around 12:30 p.m., people in the North End hear snapping sounds as rivets pop off the tank, followed by a crash as it bursts open.

SNAP! CREAK! BOOM!

What’s that sound?

It’s the tank!

It’s coming apart!

RUN!

A wave of molasses 25 feet high roars down Commercial Street at 35 miles per hour, destroying everything in its path.

HELP!

I'm stuck!

AHHH!

People rush to the scene to help. In the end, the flood claims the lives of 21 people and injures 150.

There’s someone stuck under here!

Quick, we need to get them out!

As night falls, colder temperatures cause the molasses to thicken.

Plain water isn’t washing away the molasses.

Let’s try seawater.

Salt water does the trick, but cleanup and rebuilding take months.

The U.S. Industrial Alcohol Company deflects blame and suggests someone planted a bomb at the tank.

My client knows beyond question that the tank was physically sound.

Its collapse was an act of sabotage!

A group of criminals must have blown it up with dynamite.

But police find no evidence of a bomb. A trial of the company’s responsibility begins.

I call to the stand civil engineer Charles Spofford.

I investigated the disaster.

The tank’s materials were under nearly twice as much pressure as they were designed to handle.

The court rules that the tank was poorly constructed. It orders U.S. Industrial Alcohol to pay victims and their families.

As a result of the molasses flood, Massachusetts enacts some of the country’s first building codes. Other cities and states soon adopt similar rules to ensure that structures are built properly.

Many building standards in place today trace back to the molasses disaster—including the requirement that new construction must be approved by a certified engineer.