Tony Stewart opted not to race in Sunday's Cheez-It 355 at The Glen after running over and killing an on-foot driver Saturday night during a sprint car race event.

After having originally told USA Today that Sunday would be "business as usual" for the team, Vice President of Competition for Stewart-Haas Racing Greg Zipadelli announced the three-time Sprint Cup champion would not participate in Sunday's race at Watkins Glen International in upstate New York.

"It's an emotional time right now," Zipadelli said.

Stewart also released a statement about his decision to sit out the Cheez-It 355 at The Glen saying that, "There aren't words to describe the sadness I feel about the accident that took the life of Kevin Ward Jr. It's a very emotional time for all involved, and it is the reason I've decided not to participate in today's race at Watkins Glen. My thoughts and prayers are with his family, friends and everyone affected by this tragedy."

Stewart and 20-year-old Kevin Ward Jr. were competing in an Empire Super Sprints series event Saturday night at the Canandaigua Motorsports Park when Ward Jr. hit the outside wall during Lap 14 of a 25-lap race when Stewart spun out Ward Jr.'s car, causing the yellow caution flag to be raised. USA Today reports Stewart hit and killed the 20-year-old driver after Ward exited his vehicle, who was displaying "displeasure" over getting wiped out the race as he approached Stewart's car and was struck by Stewart's vehicle, according to driver Tyler Graves and witness Adam Dulski.

NASCAR spokesman Kerry Tharp spoke on the investigation into the tragedy earlier Sunday.

"Everything that's been made available to us at this time would not preclude (Stewart) from participating in this event here today. But it's 9:30 in the morning," said Tharp.

Prior to Stewart's decision to withdraw from the race, Tharp made it a point to emphasize that it was too early to say whether Stewart would be racing at Watkins Glen International as NASCAR continued to gather information. The Empire Super Sprints series event where the incident occurred was not a NASCAR sanctioned event.

The New York Times reports that witnesses are offering different opinions about the wreck saying that some blame Ward for approaching Stewart's car while others blame Stewart.

Graves, a friend of Ward Jr., gave his account to Sporting News, having witnessed the tragedy from from the Turn 1 grandstands.

"I know Tony could see him. I know how you can see out of these cars," said Graves. "When Tony got close to him, he hit the throttle. When you hit a throttle on a sprint car, the car sets sideways. It set sideways, the right rear tire hit Kevin, Kevin was sucked underneath and was stuck under it for a second or two and then it threw him about 50 yards."

The investigation into Ward Jr.'s death is still ongoing as officials wait to gather more information.

Ontario County (N.Y.) Sheriff Philip C. Povero said Sunday afternoon that there are no charges pending against Stewart at this time and that the investigation is still ongoing. Povero said he has seen no evidence that would lead him to believe the incident was of criminal intent as of yet.

"This is an ongoing investigation of an on-track crash," said Povero early Sunday morning.

AJ Allmendinger, who beat out Marcos Ambrose to win Sunday's race, gave his condolences to the Ward family during his post-race interview on victory lane.

"We're a community here, we're thinking about you," said Allmendinger to ESPN.

You can find footage of the incident here: Video a fan shot of the Tony Stewart incident (GRAPHIC - DISCRETION IS ADVISED).