71960 Coalbrook mine accident (South Africa, 435 casualties)
A newspaper covering the Coalbrook Mine disaster (Image from Berend Schuitema)
On January 21, 1960, the town of Sasolburg was startled as the Coalbrook mine was experiencing a massive structural disaster. The mine was faced with the collapse of some 900 underground pillars meant to support the tunnel roof. This led to the collapse of about three kilometers of the mine, which ended up killing 435 people. Some half of the deaths occurred due to methane gas poisoning and some of the rescue workers that went also died.