Tony Stewart on Kevin Ward's death: 'There aren't words'

CANANDAIGUA, N.Y. (KABC) -- A driver has died after being struck by NASCAR's Tony Stewart during a sprint car event at the Canandaigua Motorsports Park in New York Saturday night.

Video from the race shows Stewart and driver Kevin Ward Jr. colliding. Moments later, Ward can be seen getting out, walking across the track and angrily pointing toward Stewart's car, before being hit. The 20-year-old Ward was pronounced dead at the hospital. Stewart was unhurt.

At this point, sheriff's officials say the investigation is not criminal and Stewart, who was questioned and released, was fully cooperative and appeared "very upset" over what had happened.

Stewart, a three-time NASCAR champion, says "there aren't words" to describe his sadness over the accident.

In a statement released by spokesman Mike Arning, Stewart says "my thoughts and prayers are with his family, friends and everyone affected by this tragedy."

Stewart was scheduled to participate in Sunday's NASCAR event at Watkins Glen, but his team announced Sunday morning that he would not take part in the race. Regan Smith drove Stewart's car instead.

"Our thoughts and prayers go out to the family, friends, and fellow competitors of Kevin Ward Jr.," NASCAR said in a statement. "We support Tony Stewart's decision to miss today's race and we will continue to respect the process and timeline of the local authorities and will continue to monitor this situation moving forward."

The Associated Press contributed to this report.