ON THE DAY OF ACCIDENT ""OFF DUTY"" EE DROVE TO THE MINE OFFICE TO CHECK ON THE AVAILABILITY OF OVERTIME FOR THE FOLLOWING DAY. WHILE AT THE MINE OFFICE TALKING THE WAREHOUSEMAN HE WAS ASKED TO GO WITH HIM TO CHECK ON LEAKING AIRCONDITIONER. AS THE EE WAS LOOKING AT THE AIR CONDITIONER, HE INADVERTENTLY STEPPED FROM THE PLYWOOD FLOOR OVER ONTO THE CEILING TILE. AS A RESULT, HE FELL