History's Sweetest Disaster

On January 15, 1919 the ground near Commercial Street in Boston, Massachusetts began to tremble. For over a decade, Boston residents had grown use to the 6-story tall iron tank at the Purity Distilling Company. The tank was used to house molasses offloaded from ships and store it for future transport by pipeline to the Purity ethanol plant in nearby Cambridge. As the ground continued to shake, the tank let out a groan akin to a massive stomach with indigestion.

Moments later, a sound reminiscent of machine gun fire rattled though the streets as one by one the rivets holing the iron panels together buckled, and over 2 million gallons of molasses poured from the ruptured tank.

The ensuing wave of molasses reached heights of 25 feet and traveled through Boston at speeds approaching 35 miles per hour. Molasses has a density of about 1.4 tones per cubic meter, 40% more density than water, resulting in the molasses having a great deal of potential energy. This energy ripped building from foundations and threw trucks into Boston Harbor.

The first rescuers to arrive at the scene was a crew of 116 sailors from the USS Nantucket that was docked at the nearby pier. They entered the knee-deep molasses and began to pull survivors out of the sticky flood. They were soon joined by the Boston Police, the Red Cross, as well as Army and Navy personal, who worked throughout the night. The injured were so numerous that a makeshift hospital was set up in a nearby building.

When rescue efforts concluded four days after the accident 21 people were confirmed dead, with another 150 injured. Cleanup from the disaster took even longer. Over the course of several weeks saltwater and sand were used to absorb, and blast away the molasses into the harbor, which was brown with molasses for several months after the explosion. It took even longer to clean the greater Boston area from the molasses. Workers, sight seers, and clean up crews themselves had tracked molasses through the streets and spread it onto subway platforms, homes, and streetcars. It was reported that “everything a Bostonian touched was sticky”.

In the aftermath of the disaster and cleanup efforts, a group of citizens brought a class action suit against the United States Industrial Alcohol Company, which had bought Purity Distilling two years prior. It was one of the first class action suits in the state. The company claimed that the tank had been blown up by a group of anarchists because some of the alcohol was used to make munitions. After over three years of hearings, the truth came out, and United States Industrial Alcohol was forced to pay up.

You likely can already assume as much, but anarchists did not blow up the tank.

Witnesses reported that tank had leaked from its first day. Purity Distilling had failed to properly test the tank, and as a result brown molasses had been seeping through the seams in the iron from the moment it entered the tank. Purity at this point could have opted to reinforce the tank. They could have added rivets. They could have welded the seams. Instead, they painted the tank brown, so the oozing molasses could not be seen.

Modern analysis has also found that the steel used to construct the tank was only half as thick as it should have been, even based on the lower construction standards of the time. The tank walls lacked manganese which made the steel more brittle, and the rivets holding it all together were also flawed.

Even with all of its flaws, the tank likely could have held up if not for one more factor. Purity Distilling had entirely neglected to pressure test the tank, or even account for increasing pressure when the tank was designed. The tank had been designed (barely) to withstand the pressure of the. Molasses inside of it. In a moment of peak irony, Purity Distilling forgot to factor in that while it was sitting awaiting transport, the molasses they intended to ferment, might just start fermenting. When sugar ferments, it releases gases, which in a confined space, increase the pressure even further. Neglecting this factor, and neglecting to pressure test the tank, ultimately led to the explosion.

As a result of their negligence Purity Distilling was ordered to pay almost $10 million in today’s dollars to victims of the disaster.

As we head toward what looks to be a more and more likely recession, now is the time to pressure test you finances. Evaluate your emergency fund. Pay off debt. Double check your long-term financial plan and goals. It’s relatively easy to manage personal finances when times are good. Pressure testing them for when times get bad is what can save you from potential disaster.

It's been over 100 years since the molasses flood. But on a hot day, the streets in some parts of Boston still bleed molasses.