CAR TRAVELING AT 25 MPH IN STRAIGHT LINE ON CITY STREET, LOUD BANG AND SHOWER OF SPARKS UNDER CAR. LOSS OF POWER BUT CAR STILL RUNNING. PULLED TO SIDE OF ROAD AND SAW SMOKE COMING OUT OF HOOD. OPENED HOOD AND ENGINE COMPARTMENT ENGULFED IN FLAMES, CLOSED HOOD AND GOT AWAY FROM CAR. WITHIN 40 SECONDS ENGINE COMPARTMENT AND CABIN TOTALLY ENGULFED IN FLAMES, CAR WAS A COMPLETE LOSS. 61,000 MILES.