When Boston Harbor was Stained Brown – The 1919 Boston Molasses Flood

By Visio Roughton

Molasses has a long, rich history in American society. A byproduct contrived from sugarcane refining, it was a common ingredient in many households. It was a cheaper sweetening agent, thus demand for the liquid intensified, especially in the early 20th century. It was imported in large quantities from the Caribbean, adding to the demand for it. As it was such an affordable sweetener, it became a key ingredient in baked goods and beverages, including rum. At an industrial level, molasses played a critical role in alcohol production, especially regarding rum and ethanol. At that time, ethanol a material used in weapons manufacturing during World War I had been in high demand. Boston became a hub for molasses storage and distribution, as it was a port city, which made it easier to import and export molasses products. 

Companies like the Purity Distilling Company, which by 1917 had become a subsidiary of the United States Industrial Alcohol Company, were one of the many businesses that stored enormous amounts of the syrup in massive tanks along the waterfront in the North End of Boston. They were strategically placed at a point that was near both shipping docks and rail lines, to facilitate the transport of molasses to distilleries and factories around the area. By 1919, despite the end of World War I a year prior, there was still a high demand for molasses products, especially under the threat of prohibition. 

The Incident:

On January 15, 1919, Boston experienced a sharp rise in temperature to over 40°F (4°C), a significant change from the freezing temperature from the previous days. On January 14th, the day before the flood, a shipment of molasses had been delivered to the tanks. To ensure an easy transfer of the molasses, it was warmed to reduce its thickness. It is theorized that the combination of the fresher and warmer molasses with the older, colder molasses that were already in the tank may have caused a thermal expansion of the molasses, which was one of the factors that led to the tank’s failure. At approximately 12:30 p.m. on the 15th, one of the main tanks burst and sent a wave of molasses through the North End. 

At first, some witnesses mistakenly believed a machine gun was involved, as the rivets that shot from the tank when it broke apart were very reminiscent of machine gun fire. 

Molasses is 40% denser than water and when the tank gave way, the wave that was released proved how destructive the dense material could be. The deluge of molasses reached 25 feet high and traveled at the highest speed of 35 mph. The force of the wave was so strong that the steel panels from the tank were slammed into the girders of the nearby Boston Elevated Railway’s Atlantic Avenue structure, momentarily tipping a streetcar off its tracks. Several blocks of the surrounding area were covered with molasses; which reached depths of 2 to 3 feet at its deepest. 

The flood left around 150 people injured and 21 dead, and several animals including horses were also injured in the incident. Many victims were crushed by flood debris or drowned in the molasses. 

In the direct aftermath of the flood, as survivors and rescue workers fought to escape the molasses, many suffered from coughing fits and other respiratory ailments as a result of the sticky air caused by the high amount of molasses. 

Aftermath:

Fireboats were brought in from the bay to spray away the sticky residue. Sand was also used to absorb the molasses and it is said that the bay was brown until the summer from the molasses. The cleaning efforts in the immediately affected area took hundreds of volunteers to complete and many weeks to complete. The overall cleanup of the city at large took even longer to complete, and this was partly because molasses had been tracked far and wide out of the accident site by rescue and cleanup crews, along with sightseers. It eventually even made its way into peoples’ homes. 

Among the first people to respond to the scene were 116 cadets from the USS Nantucket, which was docked nearby at the playground pier at the time of the tank’s collapse. The cadets waded several blocks through molasses that were knee-deep to rescue survivors while others worked to keep onlookers from obstructing the rescue efforts. 

Additional help then arrived, including the Boston Police, Red Cross, and personnel from the Army and Navy. 

Some of the Red Cross nurses made their way through the molasses to assist victims, whilst others offered to tend to those injured who had been pulled from the flood. A makeshift hospital was established in a nearby building to treat the numerous injuries. 

The amount of thick molasses present made it incredibly difficult to rescue people stuck in the residual molasses. 

Rescue operations lasted for four days before being called off. 

Many of the deceased were coated in such a thick layer of molasses they were difficult to identify, and other victims were swept into Boston Harbor so that their bodies were not discovered until three to four months after the initial flood. 

As a result of the flood, 119 Boston residents filed a class-action lawsuit against the United States Industrial Alcohol Company and it became one of the first class-action suits to be filed in Massachusetts. This also marked a significant step forward in terms of modern corporate regulations. The USIA tried to claim that the tanks had been sabotaged, citing its use in producing alcohol for munitions, but this did not succeed in court, and the company was deemed to be at fault.

Research into the accident indicated that there were a number of factors that contributed to the tank’s failure. One of the possible problems that was revealed was the possibility the tank had been defective and leaky since the first day it was put in use four years before the accident in 1915. 

It was also discovered that the tank itself was also constructed poorly and tested incorrectly. The possible fermentation from the molasses may have raised the internal pressure of the tank. The fluctuating temperatures and unusually warmer weather could have also contributed to the pressure within the tank.

The area that directly failed was found to be a manhole cover near the base of the tank. There was a high possibility that the stress within the tank had caused the outside to begin cracking to the point that it became unstable. It was filled eight times during the tank’s use, which further increased the stress the tank’s walls were under. People believe that one of the contributing factors to the disaster was the fact that the Purity Distilling Company was allegedly trying to produce a significantly higher amount of product than normal in preparation for the new regulations that would be put in place once prohibition was signed into law.

The investigation also uncovered negligent actions by Arthur Jell, USIA’s treasurer, who oversaw the tank’s construction. Jell had no architectural or engineering background and skipped essential safety measures, such as properly testing the tank. (He filled it with water, to test for leaks and wall strength, however, this was insufficient as the water is less dense than the molasses would be.) 

He also disregarded other warning signs, including the fact that the tank would groan every single time it was filled. The tank also had such constant and severe leaks that the decision was made to paint it brown to conceal it. This fact was so well known that residents at the time allegedly would even collect molasses for their personal use. In 2014 analysis of the accident showed that the walls of the tank were thinner than what the requirements for a tank of that size called for, even at that time. The brittle state of the metal walls also contributed to the cracks that sprang in the tank; cracks that originated from the faulty rivet holes, which further compromised the tank’s structure. 

The tank was never rebuilt after the disaster, and the site was later repurposed into a yard used by the Boston Elevated Railway, the predecessor of today’s Massachusetts Bay Transportation Authority. 

However today, it is now a place called Langone Park, a city-owned area. There is a small plaque in remembrance of the disaster near the sight where it occurred.  The disaster prompted significant changes in laws and regulations surrounding the construction of facilities. Most notably, it is responsible for making oversight of constructions by licensed architects and civil engineers mandatory in an effort to ensure stability for future projects.