Abstract: A NON-FLAMMABLE, WATER-BASED GLUE WAS KEPT IN A TRAILER. WHEN THE TEMPERATURE APPROACHED THE FREEZING POINT A PROPANE HEATER WAS USED TO KEEP THE GLUE WARM. THE TRAILER WAS RELATIVELY AIR TIGHT. FOR SOME REASON, THE FLAME WENT OUT. THE SAFETY SWITCH HAD BEEN TAPED IN THE "OFF" POSITION, SO THAT THE THERMOCOUPLE WAS EFFECTIVELY BYPASSED, AND GAS CONTINUED TO FLOW. WHEN EMPLOYEES #1 AND #2 SAW THAT THE FLAME HAD GONE OUT, THEY IMMEDIATELY TRIED TO RESTART IT. AN EXPLOSION AND ENSUING FLASH FIRE RESULTED, SEVERELY BURNING BOTH EMPLOYEES. SEVEN DAYS LATER, BOTH EMPLOYEES WERE STILL ALIVE, BUT THE PROGNOSIS FOR EMPLOYEE #1 IS NOT GOOD.