Local authorities have not yet released the name of the victim.
NASCAR driver Tony Stewart struck and killed another driver during a dirt track race at Canandaigua Motorsports Park in New York on Saturday night.
Ontario (NY) County sheriff Phillip C. Povero told reporters that Stewart was identified as the driver and that the victim was dead on arrival at Thompson Hospital at 11:15 p.m. ET, per Prescott Rossi of WROC-TV in Rochester. Povero did not release the name of the victim, as family members had not yet been notified.
"Mr. Stewart has been fully cooperative," Povero said. "He is very upset and confirmed his continuing cooperation."
Povero also said that the district attorney's office has been notified, but that no charges have yet been filed.
"This is an ongoing investigation of an on-track crash," Povero said.
The remainder of Saturday's Empire Super Sprints race was canceled.
"People that witnessed it were horrified. They were extremely shocked," Povero said. "The people at Canandaigua Motorsports have cooperated fully."