The technique uses a large grinder to extract the coal and creates large amounts of coal dust and methane gas , both of which are explosive . President Truman calls for thorough investigation into mine blast . Four missing miners are dead ; death toll in West Virginia coal mine disaster now at 29 . Most of the victims were working in an area where long wall construction was taking place .
President Truman calls for thorough investigation into mine blast . Four missing miners are dead ; death toll in West Virginia coal mine disaster now at 29 . Most of the victims were working in an area where long wall construction was taking place .