Abstract: EMPLOYEES #1 AND #2 WERE TRYING TO RELIGHT A KILN WHICH HAD SHUT DOWN AT 4:40 AM. AT 7:30 AM EMPLOYEE #2 HAD CLOSED THE BURNER VALVES. AT 9 AM THEY ATTEMPTED TO RELIGHT THE KILN. UNKNOWN TO THE EMPLOYEES A BYPASS LINE AROUND THE AUTOMATIC SHUT-OFF VALVE WAS LEAKING NATURAL GAS. THIS MEANT THAT FROM THE TIME THE KILN SHUT OFF TILL ABOUT 7:30 GAS HAD BEEN FLOWING THROUGH THE OPEN BURNER VALVES INTO THE KILN. EMPLOYEE #2 WAS ON TOP OF THE BEEHIVE KILN AT ONE OF THE BURNERS. EMPLOYEE #1 WAS ON THE GROUND BY THE AUTOMATIC SHUT OFF. EMPLOYEE #2 ACTIVATED THE IGNITION SOURCE FOR THE BURNER. AN EXPLOSION OCCURRED, BLOWING THE CROWN OFF THE KILN. THE EMPLOYEES SUSTAINED MINOR INJURIES, MOSTLY CUTS REQUIRING STITCHES. THE COMPANY NEEDS TO INSTITUTE WRITTEN RELIGHT PROCEDURES. THE BYPASS LINE CUT-OFF VALVE SHOULD BE CLOSED WHEN THE BYPASS SOLENOID VALVE IS NOT BEING USED. A SYSTEM IS NEEDED TO MONITOR THE CONCENTRATION OF METHANE IN THE KILN. THE COMPANY NEEDS TO INSTITUTE MAINTENANCE PROCEDURES FOR CHECKING THE PROPER FUNCTIONING OF VALVES AND OTHER SAFETY EQUIPMENT.