In January 1919, what disaster hit Boston, Massachusetts?

It might seem like something out of a horror film, but this was a genuine disaster that befell the citizens of Boston: a massive wave of black treacle (molasses ). On 15 January 1919 a huge 8.7 million litre holding tank in a treacle factory burst catastrophically. The sudden release of the treacle and the pressure in the tank created a tsunami-like wave: witnesses reported the wall-like treacle wave was 10 metres tall.

Buildings close to the wave’s peak strength were completely destroyed with wreckage scattered more than fifty metres from the site. Secondary damage was brought about by the shards of the tank falling down: one such shard fell on a fire station and crushed the building along with the three firemen inside. The total death toll was 21 citizens with another 150 injured.