The tsunami leveled an entire neighborhood within seconds.

In today's world of notifications and alerts, it seems nearly unfathomable that a sea of molasses would cause the damage it did. However, on January 15th, 1919, Boston endured the Great Molasses Flood.

According to NBC 10 Boston, initial waves soared as high as 25 feet. Temperature had risen above 40 degrees at the Purity Distilling Company facility after a bitter cold snap. The flood started when a giant storage tank carrying more than 2.3 million gallons of molasses ruptured, sending a giant wave of goop crashing through the cobblestone streets of the North End. According to Wikipedia, molasses is about 1.5 times more dense than water. While travelling at over 35 mph, it rushed through the streets waist deep, and swept up everything in its wake. By the time things settled, about 150 people were injured, and 21 people and several horses were killed. Some were crushed and drowned by the molasses or by the debris that it carried.

NBC 10 Boston said Purity Distilling's parent company, U.S. Industrial Alcohol, argued that anarchists planted a bomb that shredded the tank. But investigators concluded the tank's construction was faulty. A judge ordered it to pay $300,000, or about $4.5 million today for damages.