What happened
A witness driving westbound near the accident site observed the aircraft flying approximately five feet above the tree line, heading south-southwest. The aircraft struck trees on the east side of a four-lane road before impacting the median between the northbound and southbound lanes, resulting in a post-impact fire.
During the downwind leg to runway 24, the pilot/passenger observed the pilot-in-command (the instructor) turn the right engine fuel selector to the OFF position while turning to long final. The second pilot, seated in the right front seat, reduced power to begin a descent but did not immediately realize an engine failure had occurred. As the aircraft began to lose airspeed, the stall warning light activated. The occupants noted the loss of speed and the instructor repeatedly called for attention to the airspeed. After realizing the aircraft was descending at an excessive rate, the pilot-in-command took control in an attempt to recover, but the aircraft struck the trees and road. All 3 occupants sustained injuries so severe that they were unable to provide statements to investigators.
The investigation
Examination of the wreckage confirmed that the right engine fuel selector was in the OFF position both in the cockpit and at the wing selector valve. The right propeller was found in the feathered position. Investigators found no visual discrepancies on the airframe, flight controls, or engines prior to impact. While the occupants could not be interviewed, the pilot-in-command's wife stated that her husband had previously indicated there were no mechanical problems with the engines or airframe. An FAA inspector confirmed that the pilot seated in the left front seat was the instructor and pilot-in-command.