WHILE MINING A CURRENT HOLE, THE COAL QUALITY TURNED BAD AND AUGER ENGINE SPED UP. TO DETERMINE IF THEY HAD POSSIBLY INTERSECTED THE PREVIOUS HOLE OR GOTTEN INOT THE ROOF OR FLOOR, THEY HAD TO OPEN THE PREVIOUS HOLE TO SEE AND LISTEN. THIS HOLE HAD BEEN CORKED BY A BULLDOZER WHILE CLEANING UP. WHEN OPENED, ACCUMULATED GAS IGNITED ON THE AUGER'S INERT GAS BURNER & BURNED < 60 SEC.