On September 6, 1997, at 1103 eastern daylight time (edt), a North American/Aero Classics P-51D, N6345T, operated by a commercial pilot, was destroyed when during cruise flight, the airplane's engine lost power. While maneuvering west of Monroe, Michigan, the airplane struck a powerline and subsequently impacted the terrain. Visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under 14 CFR Part 91. There was no flight plan on file. The pilot and passenger on board were fatally injured. The flight originated at Toledo, Ohio, at 1053 edt, and was en route to Ypsilanti, Michigan. A witness attending the Toledo Air Show at Toledo Express Airport, Ohio, videotaped the airplane takeoff at approximately 1053 edt. The witness said that in the video of the airplane white/gray smoke can be seen coming from the rear of the airplane. The witness provided a copy of the video to the National Transportation Safety Board for review. Several witnesses observed the airplane maneuvering west of Monroe, Michigan just prior to the accident. One witness was in his vehicle traveling eastbound on M-50, an east-west running paved road, at approximately 1100 edt when he heard a "loud vibration/screaming noise and then observed a plane fly approximately 40 feet along the treetops just north of M-50. The plane had heavy white and black smoke pouring from the rear. The plane banked right, hit a powerline and plunged to the ground." The witness describes two separate trails of smoke, one white and one black. Two other witnesses, who were traveling in their car westbound on Michigan State Highway M-50, observed the airplane flying eastbound at very low altitude. The driver of the car said that she saw the airplane coming toward them at "tree-top level." She recalled saying to her husband (the second witness in the car). "That plane is mighty low." She said that the airplane was trailing one steady stream of dark smoke. The airplane made a turn to the right (south), hit the wires, and went nose first into a ditch that was just before the road. The other witness in the car observed the airplane after his wife brought it to his attention. "I looked up and saw the airplane flying just above the wires. The airplane made an abrupt right turn toward the south, jerked a bit, and then hit the ground. The plane exploded and the engine of the plane landed on the road. A Federal Aviation Administration (FAA) inspector examined the wreckage at the site on September 6, 1997. The inspector found the remains of the airplane resting in a drainage ditch on the north side of Michigan Highway M-50. The airplane had broken apart into several pieces and was spread out over a 1/4-mile area. The airplane's right wing was found resting in some brush at the base of east-west running powerlines approximately 100 feet north of M-50. The powerlines were severed in that area. There was an 8-inch chordwise-running gash in the leading edge of the left wing at 18 inches inboard of the wingtip. Five empty containers of anti-freeze were found in the left wing locker. The field between the powerlines and the road was scorched. The cockpit and left wing were intact and resting in the ditch. The cockpit area was destroyed and charred. The left wing was intact. The left flap was bent upward near the outboard edge. The aft fuselage and empennage had broken off aft of the cockpit. The fuselage was bent upward and crushed aft at the fracture. The empennage was intact. The left horizontal stabilizer and elevator showed minor damage. The forward fuselage and engine cowling were broken open and charred. The lower portion of the airplane which contained the radiator had broken off and was resting next to the ditch. The radiator remained intact. The engine had broken off and was found resting in the westbound lane of M-50. The propeller was broken off from the engine. One of the four blades was bent near the spinner, approximately 70- degrees. All blades showed chordwise scratches. One side of the spinner was crushed inward. Flight control continuity was confirmed. The engine was retained for further examination. The airplane's engine was examined by the FAA, on September 9, 1997, at Monroe, Michigan. The examination revealed a hole in front of the crankcase, on the right side, at the crankshaft level. The right front connecting rod was found broken near the journal. The piston in that cylinder was located near the bottom of its stroke. The bottom of the piston showed impact damage. Metal specks were observed on the cylinders. The engine exhaust ports showed residue which resembled molten metal droplets. The radiator was also examined. It showed a small amount of coolant inside. Fluid carrying lines to the unit were crushed. An autopsy of the pilot was conducted by the Monroe County, Michigan Medical Examiner, on September 7, 1997, at Monroe, Michigan. The results of FAA toxicology testing of specimens from the pilot were negative for all tests conducted. Examination of the videotape provided to the National Transportation Safety Board showed the airplane taking off trailing white vapor. The vapor appeared to originate beneath the airplane, just behind the airplane's air intake.