THE PLT WAS INSTRUCTED TO ENTER A LEFT BASE LEG IN THE TRAFFIC PATTERN TO LAND ON RWY 25, FOR THE PURPOSE OF MAINTAINING SEPARATION FROM OTHER LANDING TRAFFIC. THE AIR TRAFFIC CONTROLLER ADDITIONALLY INSTRUCTED THE PLT TO MAKE THE BASE LEG SQUARE. REVIEW OF THE AIRPLANE'S FLIGHT PATH AS DEPICTED BY FAA DRAWINGS ILLUSTRATED AN APPROACH PATTERN SIMILAR TO A LONG FINAL APPROACH. WITNESSES ON THE GROUND ABOUT 1 1/2 MILES FROM THE AIRPORT ON THE RWY 25 EXTENDED CENTERLINE STATED THAT THE AIRPLANE OVERFLEW THEIR HOMES AT A LOW ALTITUDE. THERE WERE NO REPORTS OF UNUSUAL ENGINE NOISES. AIR TRAFFIC CONTROLLERS OBSERVED THE AIRPLANE IN A RAPID DESCENT IMMEDIATELY BEFORE THE ACCIDENT. THERE WAS NO EVIDENCE OF MECHANICAL FAILURE OR MALFUNCTION WITH THE AIRPLANE BEFORE THE ACCIDENT. THE AZIMUTH AND ANGLE ABOVE THE HORIZON OF THE SUN WAS 241.1 DEG AND 2.8 DEG. RESPECTIVELY.