Because some dumb guy farted and sent a gas rocket that caused the coal to crash down.
Coal Glen mine disaster happened in 1925.
Mitsui Miike Coal Mine disaster happened in 1963.
Mina de Barroterán coal mine disaster happened in 1969.
Lack of safety precautions, blasts were set in the wrong places.
September 22 1934 Coal Mine disaster.
Good Coal, most likely black coal
It was under the control of the National Coal Board
Coal workers pneumoconiosis (CWP), is caused by inhaling coal dust.
A coal mine is typically referred to as a coal mine.
divide it by 1000 (there are 1000 mm in a meter)
The Felling mine disaster occurred when firedamp ignited and the resulting coal dust explosion sent a devastating blast throughout the mine and up its two mine shafts, the John pit and the William pit, named after the Brandling brothers who owned the colliery.
to mine coal...