Abstract: TWO EMPLOYEES WERE ASSIGNED TO REMOVE A 12 INCH SQUARE OF SOLIDIFIED ASPHALT FROM THE INSIDE OF A TANK TRUCK, SO THAT WELDING COULD BE DONE ON THE TANK. THE TANK HAD BEEN COOLED AND VENTILATED. THEY STARTED TO CHIP AWAY AT THE ASPHALT CHIP WITH AN ELECTRIC HAMMER DRILL, BUT THE ASPHALT WAS SLIGHTLY STICKY AND NOT EASILY BROKEN UP. EMPLOYEE #2 INSTRUCTED EMPLOYEE #1 TO GET A 20 POUND CYLINDER OF LP GAS AND BRING IT INTO THE TANK. EMPLOYEE #2 TOOK THE TANK AND SPRAYED LP GAS ONTO THE ASPHALT IN AN EFFORT TO FREEZE IT. EACH TIME THEY WOULD VENTILATE THE GAS BEFORE USING THE HAMMER DRILL. ABOUT THE 6TH TIME THAT THIS PROCEDURE WAS USED, THE LP GAS WAS APPARENTLY NOT VENTED SUFFICIENTLY AND IT IGNITED, BURNING THE TWO EMPLOYEES. NONE OF THE SUPERVISORY PERSONNEL WERE AWARE THAT THE LP GAS WAS BEING USED IN THE TANK.