An autopsy has concluded that driver Jason Leffler died of blunt-force trauma to his neck, an injury sustained during a wreck Wednesday night at Bridgeport (N.J.) Speedway.
Leffler's car struck the wall at Bridgeport following a tire blowout, according to witnesses at the track. Leffler had to be extricated from the wreckage and was airlifted to a local hospital. Authorities have not released details about Leffler's condition when he was extricated from the vehicle.
Blunt force trauma is the application of extreme force to the body, and is distinguished from penetrating trauma, in which an object enters the body. It is the same cause of death as IndyCar driver Dan Wheldon, who died of blunt force trauma to the head during an IndyCar race in Las Vegas in 2001. Dale Earnhardt Sr., by contrast, died of a basilar skull fracture, though the proximal cause, collision with an immovable object, was the same as in Leffler's case.
Leffler's team indicated that he was wearing a Simpson Hybrid neck-and-head restraint system, one of six approved for use in NASCAR races. There has been no word on the system's functioning in Leffler's crash.
New Jersey state police continue to investigate the accident.
Drivers across all of NASCAR's series will be honoring Leffler on their cars this weekend.
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