(CBS Sports) NASCAR driver Jason Leffler died from a blunt force neck injury when his car hit a wall at a sprint car race Wednesday night, an autopsy revealed, according to USA Today.
The Delaware County (Pa.) Medical Examiner ruled the cause of death was the neck injury, but New Jersey State Police continue to investigate the cause of the accident at the Bridgeport Speedway dirt track.
Leffler, 37, made 73 starts in the Sprint Cup Series and was a two-time winner on the Nationwide Circuit.
His car left the track during a preliminary heat Wednesday night, flipped and struck a wall, authorities said. Leffler had to be extricated from his car.
The Long Beach, Calif., native is survived by his 5-year-old son, Charlie Dean.