DURING THE RETURN FLIGHT TO SAN JOSE AND SUBSEQUENT DESCENT AND APPROACH TO THE LONG BEACH AIRPORT, THE TWO PILOTS EXPERIENCED, IN SUCCESSION, A FAILURE OF THE TURBOCHARGER SYSTEM, LOSS OF AN ALTERNATOR, LOSS OF ENGINE OIL PRESSURE, AN UNSAFE LANDING GEAR INDICATION, AND AN IN-FLIGHT FIRE FOLLOWED BY THE LOSS OF ENGINE POWER DURING A NIGHT TIME CIRCLING APPROACH TO AN UNFAMILIAR AIRPORT IN VISUAL METEOROLOGICAL CONDITIONS. THE AIRCRAFT CRASHED ONTO THE SOUTHBOUND LANES OF THE SAN DIEGO FREEWAY AT LONG BEACH AFTER MAKING A FLYBY OF THE TOWER TO CONFIRM THE LANDING GEAR POSITION. THE INVESTIGATION REVEALED AN IMPROPERLY INSTALLED TURBOCHARGER, A CRACKED MANIFOLD EXHAUST, A BURNED MAIN POWER LEAD, A SEPARATED CYLINDER, AND A LOW FLUID LEVEL IN THE HYDRAULIC RESERVOIR. TWO YEARS PRIOR TO THIS ACCIDENT, THE INSTRUCTOR PILOT MADE AN UNINTENTIONAL GEAR UP LANDING IN ANOTHER ACFT. ONE YEAR PRIOR TO THIS ACCIDENT THE FAA REVOKED THE MECHANIC'S INSPECTION AUTHORIZATION.