On March 21, 2009, approximately 1630 central daylight time, a Beech A36, N8120R, was substantially damaged during a collision with terrain and vehicles following a loss of engine power and subsequent forced landing at Laredo, Texas. The local flight departed Laredo International Airport (LRD), Laredo, Texas, approximately 1530 and remained in the traffic pattern. The airplane was owned and operated by Yvoden Inc. The certified flight instructor (CFI) sustained minor injuries and the non-rated passenger/owner received serious injuries. Visual meteorological conditions prevailed and no flight plan was filed for the Title 14 Code of Federal Regulations Part 91 personal flight. According to the CFI, while in the traffic pattern, about 800 feet above ground level, the engine "hesitated" and the CFI directed the non-rated passenger, who was sitting in the left seat, to change the fuel selector valve to the right tank which contained an estimated 25 gallons of fuel. The engine stopped producing power and when the pilots could not restart the engine, the CFI performed a forced landing to an apartment parking lot. During the forced landing, the airplane struck two vehicles before coming to rest in the upright position. Both wings sustained multiple impacts and the engine was torn away at the firewall. Both wing fuel tanks were breeched. An on-scene examination of the airplane by a Federal Aviation Administration (FAA) inspector failed to reveal any airframe or engine anomaly. Damage to the fuel tanks prevented a determination of fuel remaining. The airplane's fuel selector was removed and shipped to Wichita, Kansas, for an examination at Hawker Beechcraft's facilities. Testing of the fuel selector was accomplished by inspectors from the FAA and technical representatives from Hawker Beechcraft. When the acceptance test procedure was conducted, the fuel selector seeped fuel up the selector shaft when pressure was applied and the selector was in the off-position. The valve did not leak when a tank position was selected. Valve selector detents did not have a "crisp" feel, however, all detents were readily identifiable, and the selector had no obstruction to movement. When disassembled and inspected, the shaft seal was found to be intact, but the shaft was found to be worn. Despite the anomaly of seeping fuel in the "off" position when pressure was applied, the fuel selector operated normally and would have directed fuel from the selected tank to the engine. In an interview with FAA inspectors, the pilot reported that he did not use the boost pump during the restart attempt. A review of the pilot's operating handbook (POH) revealed that the second step of the Engine Failure: After Liftoff and In Flight, is "Auxiliary Fuel Pump - ON." In addition, the non-rated passenger reported that the CFI switched the tanks several times to ensure that the fuel selector was seated in the right fuel tank detent.