DURING EN ROUTE DESCENT THE PLT TOLD THE RADAR CONTROLLER THT HE HAD LOST AN ENG AND COULD NOT HOLD ALT. WITNESSES SAW THE ACFT DESCENDING TOWARD HILLY TERRAIN, BEGIN A RIGHT TURN, THEN ABRUPTLY PITCH DOWN AND ROLL RIGHT TO IMPACT IN A RESIDENCE YARD ON THE RIGHT WING TIP. THE ACFT IS EQUIPPED WITH MAIN AND AUX FUEL TANKS IN EACH WING. A SELECTOR SWITCH DETERMINES WHETHER THE MAIN OR AUX TANK FUEL LEVELS ARE DISPLAYED ON THE FUEL GAGES. EXAMINATION OF THE ACFT REVEALED THAT THE FUEL SELECTORS WERE POSITIONED ON THE AUX TANKS WHILE THE FUEL GAGE WAS SELECTED TO THE MAIN TANKS. NO FUEL WAS FOUND IN THE AUX TANKS, WHILE ABOUT 10 GALLONS OF FUEL WERE FOUND IN THE MAIN TANKS. THE LEFT ENG FUEL LINESCONTAINED NO FUEL, WHILE THE RIGHT ENG LINES HAD FUEL. EXAMINATION OF THE PROPELLER HUBS REVEALED THAT THE RIGHT PROPELLER WAS IN THE FEATHERED POSITION WHILE THE LEFT PROPELLER WAS IN THE HIGH PITCH RANGE.