During the early part of the 20th Century, in the North End of Boston, Massachusetts¹, the United States Alcohol Company owned a distillery that featured a large steel molasses² storage tank. 52 feet in height and 90 feet in diameter, the tank was filled to capacity with 2.3 million gallons of molasses when at 12.30pm on 15 January, 1919, it burst open with a tremendous roar.

The Path of Destruction

When the tank exploded, chunks of metal were sent flying in all directions. One large piece smashed through a support for an elevated railroad. Luckily, an alert train driver managed to halt his train moments before it reached the broken tracks.

As the tank was ripped apart, a huge wall of molasses came pouring out. The wall was approximately 15 to 20 feet high and reached speeds of up to 35 miles per hour in the area around the tank. This large mass of sticky goo was soon pouring into the streets of Boston destroying everything in its path. The wave knocked a firehouse off its foundation and destroyed another municipal building. At least a dozen city workers were trapped in the second building. Cellars in people's homes were filled up with molasses, while anybody who stood in its destructive path was sucked in to the seething mess. A horse-drawn wagon was picked up by the wave and slammed into a fence. Both the horses and the people became stuck. Trolley cars were picked up and smashed. People were crushed within their houses and others became stuck in the molasses. A few intrepid souls tried to swim in the sticky goo but without success. Some of the stuff plunged into the Boston Harbour taking wreckage with it. By the end of the day, many buildings and roads were covered with molasses.

Rescue and Clean up

Rescue workers were already on the scene when the molasses finally came to a rest. People involved in the rescue work included the police, men from the harbour patrol ship, military men from a nearby US Army base, and ambulances full of Red Cross volunteers. They all plunged into the mess and within an hour they were all covered with the sticky goo. The rescue teams had a very difficult time walking through the mess and many of them had their boots sucked right off their feet. Later in the day, when the temperature dropped and the molasses began to stiffen a little bit, it became harder for the rescue teams to pull the trapped people out. Many trapped people had to be cut out of their clothing in order to get free. Sadly, the trapped horses had to be shot by the police because the rescue workers were not able to free them.

The next day marked the beginning of the long and tedious clean up process. Firemen tackled the sticky mess with hoses. The water from the fire hydrants was no use because the fresh water would just wash right off of the molasses. To make any progress, they had to use salt water from the harbour. When hit by salt water, the molasses frothed up all yellow and sudsy. It took months to pump the molasses out of cellars with hydraulic siphons. No matter how hard they tried, the clean up crews could not get rid of all of the sticky goo.

Tragically, 21 people were killed and 150 others were injured. Some were suffocated by the molasses, some were crushed by falling objects, while the wave swept others into the harbour. Two of the victims were not found until four days later. By that time their bodies were so battered and glazed that they could not be identified at first.

The Aftermath

Even after the clean up crews were finished, residue stickiness remained for months. Wherever people walked their shoes would get stuck in the leftover goo. The molasses was spread by work crews well beyond where the actual wave of molasses stopped and for months every doorknob, every telephone, every chair, and every table was sticky. The Boston Harbor was also stained brown for six months and the smell of molasses could be detected in the city for even longer.

Eventually, the distillery was brought to court. There were 119 different lawsuits lodged against them. The United States Alcohol Company spent over $50,000 on expert witness fees, claiming that the accident was not caused by a structural weakness but that bomb-throwing anarchists were responsible for the mess. Though there were some bomb-throwing anarchists around at the time, there was no proof that any of them had thrown a bomb at the molasses tank. Even without any proof of their claim, the distillery still thought that they would win the case because most of the 21 people who died and many of the people who were suing them were poor.

The hearings lasted for 300 days and more than 3000 witnesses were called to the stand to testify. 45,000 pages of testimony and arguments were recorded. In the end, the owners of the tank were ordered to pay nearly $1 million in damages. An enormous amount of money in 1919.

The Cause

It was concluded that poor construction and overfilling of the tank were to blame for this disaster. When investigators went to City Hall to look at the plans that were filed when the tank was built they couldn't find any. The city's building inspectors said that no building plans were required because the tank was not a building but an industrial device. The industrial department people said that it was not an industrial device but a structure. It soon became obvious that the tank was built with no plans approved and no government inspectors involved.

Another widely-discussed theory was that the molasses had expanded due to a sudden increase in air temperature. The day before the incident it was only 2° Fahrenheit. On the day of the disaster the temperature rose to 40° Fahrenheit.