On May 4, 2007, about 2030 Pacific daylight time, a Piper PA-28-181, N2834U, lost engine power and collided with obstacles during a forced landing near Las Vegas, Nevada. Trojan Aviation LLC, Farmington, New Mexico, was operating the airplane under the provisions of 14 CFR Part 91. The commercial pilot and one passenger were not injured; the airplane sustained substantial damage. The cross-country personal flight departed Four Corners Regional Airport, Farmington (FMN), about 1700 mountain daylight time, with a planned destination of McCarran International Airport (LAS), Las Vegas. Visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan had been filed. The pilot submitted a written report. He stated that after an uneventful 3.9-hour flight he was on 2-mile final for runway 1L at LAS, when the engine lost power. He placed the mixture control full forward, turned the boost pump on, and verified that the magnetos were on. In a statement to the FAA accident coordinator, he indicated that he switched to the right fuel tank as part of the checklist, and the engine and propeller stopped. Just prior to landing, he turned the fuel selector to the OFF position, and turned off all electrical systems except the radios and master switch. He secured them after landing. The airplane touched down on Las Vegas Boulevard's northbound lane, which was empty. Just prior to touchdown, a vehicle turned into his path. The airplane hit that car plus two other vehicles. The FAA inspector noted that the right wing separated, and the fuel tank ruptured. He did not observe any fuel in the tank remnants or spillage in the vicinity. He said that the left wing was intact, and contained about 10 gallons of fuel. The pilot told the FAA that he switched tanks after every hour of flight. The last change was to the left tank at CROWE intersection, approximately 30 minutes prior to arrival. He later told an NTSB investigator that the right tank still contained fuel prior to switching to the left tank. The pilot met with the FAA a week later. He stated that throughout the descent the engine was at reduced power, and he did not use carburetor heat. In a telephone conversation with the Safety Board, he stated that 30 minutes prior to his arrival, at approximately 12,000 feet, he encountered light structural icing. He descended to 10,000 feet, and the ice dissipated; he noted the temperature during the encounter to be 0 degrees Celsius. Throughout his approach, he encountered intermittent cloud obscuration. Review of a carburetor icing probability chart disclosed that the temperature and dew point reported by the airport was outside of chart area predicting the possibility of carburetor ice. A maintenance technician examined the engine under the supervision of the FAA. He plumbed a 5-gallon gas can into the airplane's fuel system. He energized the electric pump, and confirmed 5 psi on the fuel pressure gauge. He started the engine within three revolutions of the propeller, and allowed the engine to reach operating temperature. He ran the engine up to 1,800 rpm, and completed a magneto check. Both magnetos dropped about 70 rpm. He then reduced the power to idle, and the engine stabilized at 850 rpm. He checked acceleration from idle to maximum power, and the engine accelerated normally. He repeated this test three times, and the engine responded without hesitating or stalling. Upon shutdown, the idle rpm rise was normal. In his opinion, there were no discrepancies or anomalies that accounted for the loss of engine power.