WE ARE AN INSURANCE CARRIER. OUR INSURED DRIVER REAR ENDED ANOTHER VEHICLE. THERE WERE NO PASSENGERS IN HIS VEHICLE. 20 MINUTES OR SO AFTER THE ACCIDENT THE PASSENGER SIDE SEATBELT AREA CAUGHT FIRE. NO ONE WAS IN THE VEHICLE, THE POLICE OFFICER WAS ABLE TO PUT OUT THE FIRE. THE SIDE OF THE SEAT , DOOR AND FLOOR NEAR THE SEATBELT IS BURNED.