21906 Courrieres Coalmine accident (France, 1099 casualties)
Courrières mine rescue workers with Guglielminetti-Drager breathing equipment
An explosion at the Courrieres Coalmine in northern France killed 1,099 people, including many citizens that were on the surface. The explosion occurred due to fissures in the walls of the mine. These fissures allowed flammable gasses to permeate much of the mine, which, unfortunately, made this a disaster just waiting to happen. To date the main theory behind the explosion is that a miner must have ignited his methane-fueled lamp while surrounded by the flammable gasses within the mine.