According to authorities, Kevin Ward Jr. died from injuries he suffered at the Empire Super Sprints series event at the Canandaigua Motorsports Park.
After his sprint car hit the outside wall during lap 14 of the 25-lap race, a video of the incident shows Ward out of his crashed car and walking on the track toward the race cars, which had slowed for a yellow flag. Ward appears to be yelling as he points a finger, and one car swerves to avoid Ward on the track.
Stewart's car then passes close to Ward and it looks like the right tire hits him. An ambulance then took Ward to a hospital, but he died before the ambulance arrived.
Ontario County Sheriff Philip C. Povero told reporters that Stewart has "fully cooperated" with the investigation and that he "acknowledges the collision with the driver."
Stewart, a three-time champion in NASCAR's top division, has since pulled out of Sunday's NASCAR event in Watkins Glen, N.Y.
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