-- NASCAR driver Tony Stewart said "there aren't words" for how sad he feels about the accident in which fellow driver Kevin Ward Jr. was struck and killed during a race.
The three-time NASCAR champ pulled out of a race he was scheduled to drive in Sunday, and racing officials and law enforcement were investigating the incident.
"There aren't words to describe the sadness I feel about the accident that took the life of Kevin Ward Jr.," Stewart said in a statement released Sunday. "It's a very emotional time for all involved. ... My thoughts and prayers are with his family, friends and everyone affected by this tragedy."
Stewart decided to not participate in NASCAR's Sprint Cup race at Watkins Glen, N.Y. The race would have been critical for Stewart's championship chances, according to ESPN.
Ward had exited his car Saturday night during a race to confront Stewart on the track when he was struck by Stewart's car.
Stewart, 43, had been driving behind another car that was able to swerve to avoid Ward. It appears that Stewart struck Ward as he was trying to drive past him, witnesses said.
Officials said that the cars were going at around 30 to 35 mph at the time Ward was hit.
Ward was pronounced dead Saturday night after being taken to a hospital. He was 20 years old.
Stewart has been cooperating with police and appeared "very upset" over what happened, Ontario County Sheriff Philip Povero told ESPN.
Ontario County police plan to complete a reconstruction of the crash using video and other visual evidence.
Police are not conducting a criminal investigation against Stewart, the sheriff said.
There are "no facts in hand that indicate criminal intent," Povero said.
"This is right now being investigated as an on-track crash and I don't want to infer that there are criminal charges pending," Povero told ESPN. "When the investigation is completed, we will sit down with the district attorney and review it. But I want to make it very clear: There are no criminal charges pending at this time.
"Stewart is free to go about his business," Povero said.
Investigators were reconstructing the accident and looking into everything from lighting to track conditions, Povero added.