PICKED UP APPROXIMATELY ONE HALF CORD OF WOOD USING MY UTILITY TRAILER, OVER-DRIVE DISABLED WHEN PULLING TRAILER. BACKED TRAILER INTO YARD TO UNLOAD THE ALREADY SEASONED AND SPLIT WOOD. PUT JEEP INTO PARK, ENGAGED THE PARKING BRAKE AND LEFT THE JEEP TO DROP THE TRAILER, HEARD A POP AND FLAMES BEGAN TO SHOOT OUT FROM UNDER THE JEEP. I REACHED INTO THE VEHICLE TO TURN OFF THE ENGINE AND REMOVE THE KEY. I HEARD ANOTHER POP AND SAW THAT FLAMES WERE NOW SHOOTING INTO THE ENGINE COMPARTMENT. I RAN INTO MY HOUSE TO GET A FIRE EXTINGUISHER, CAME BACK OUT, OPENED THE HOOD CAREFULLY AND BEGAN TO TRY AND EXTINGUISH THE FLAME. IN ORDER TO FULLY PUT OUT THE FIRE IT TOOK THE FIRE EXTINGUISHER AND MULTIPLE BUCKETS OF WATER. AFTER THE FIRE WAS FULLY EXTINGUISHED I CONTACTED MY INSURANCE CARRIER.