BRIDGEPORT, N.J. -- New Jersey State Police are trying to determine the cause of a dirt track crash that killed NASCAR driver Jason Leffler.

Leffler died after the crash at southern New Jersey's Bridgeport Speedway on Wednesday.

A spectator, Chris Taitt, says he was at the race but looking the other way when the crash occurred. He says Leffler had been in second place, apart from other cars when his car slammed into a wall at a turn. He says the wing on the car was "flattened like a pancake," and the seat appeared to be displaced.

Many drivers, owners and sponsors in NASCAR are remembering Leffler as a loving father to his 5-year-old son, an open person and a versatile driver.