The Beer Flood Caused by One Broken HoopA single metal ring's failure killed eight people.

From the show

It really happened

A tiny, overlooked flaw in a massive beer vat triggered a disaster that seems almost unbelievable. In 1814, the failure of one iron band on a 22-foot-tall fermentation tank set off a chain reaction, unleashing a 15-foot wave of porter into a poor London neighborhood. The bizarre industrial accident destroyed homes and killed eight residents, but a court later ruled it an "Act of God," absolving the brewery of all responsibility.