Updated at 3:15 p.m. with Stewart, Ward family statements

Tony Stewart changed his mind Sunday morning, deciding not to drive in a NASCAR race 12 hours after his car struck and killed driver Kevin Ward Jr. during a dirt-track race in Canandaigua, N.Y.

The announcement came not from Stewart but from Greg Zipadelli, the racing competition director for Stewart-Haas Racing. The decision comes hours after Zipadelli said today’s Sprint Cup race at nearby Watkins Glen would be “business as usual” for the team. That phrase was being met with increasing criticism as the morning wore on and video of the horrific incident was shown.

“It’s just an unbelievable tragedy. Our hearts go out to, obviously, Kevin and his family — thoughts and prayers. This is a very tough, very emotional time for everybody — his family, our family at Stewart-Haas, Tony Stewart. With that being said, we feel that as a group Tony will not drive today,” Zipadelli told reporters about 12 hours after the fatal crash.

“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.”

The change of heart about racing came Sunday morning.

“We talked last night and realizing going through the night — [we] gave Tony some time to sleep on it and I met with him this morning,” Zipadelli said when asked whether the decision was the team’s or Stewart’s. “He feels strongly that this is the right thing to do. We at HSR support it and agree with it. Like I said, it’s a difficult time, for both parties. There’s not a lot you can do. All you do is what you feel is right. This is what we feel is right and we’re supporting Tony in it.”

Zipadelli said he and other team members spoke with Stewart into the night and they opted to have Regan Smith replace Stewart.

“There was a few of us who were in there just supporting him. He’s a brother to me, you know what I mean? He’s way more than a boss. He’s going through a tough time. It’s emotional for him. We as a group support him and feel like he’s doing the right thing. We’ll move on from this.”

Although Stewart has not spoken, the Ontario County sheriff described Stewart as “visibly shaken” in a news conference Sunday morning. “Mr. Stewart has, again, fully cooperated with the police officers that are investigating,” Philip C. Povero said. “He was visibly shaken by this incident and has promised his continuing cooperation in this investigation.”

No charges have been filed against Stewart him in connection with the death of Ward, who was 20.

“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 said. “I would only say that the investigation–when it 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. This is an ongoing investigation.”

Stewart has made no secret of his passion for dirt-track racing and he drives on dirt tracks as often as possible — even to the detriment of his own health. He suffered a badly broken leg in a race a little over a year ago and was involved in a big crash at the same Canandaigua Motorsports Park track last year.

At around 10:30 Saturday night, Stewart and Ward bumped cars during the 25-lap race, with Ward’s car  getting a flat tire from a collision with the wall. With the caution flag out, Ward stepped from the car onto the track, waving his arms and pointing at Stewart. Ward was taken to a local hospital, where he was pronounced dead at about 11:15 p.m. A witness who is a sprint-car driver and friend of Ward’s described what happened to Bob Pockrass of the Sporting News:

“Tony pinched him into the front-stretch wall, a racing thing,” Graves said. “The right rear tire went down, he spun on the exit of (Turn) 2. They threw the caution and everything was toned down. Kevin got out of his car. … He was throwing his arms up all over the place at Tony for most of the corner.
“I know Tony could see him. I know how you can see out of these cars. 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.”

Video of of the incident shows Ward wearing black and walking onto the poorly-lit track. (Warning: the video is disturbing.)

Finally, after a morning of “business as usual,” there was the realization that this was anything but another day of racin’. Offering a glimpse of how Stewart and his handlers were affected by this, Zipadelli grew emotional near the end of his news conference, concluding, “I support Tony Stewart. I think I’ve shown that over the last 18 years.”

In a statement to ABC affiliate WHAM, Ward’s family said: “We appreciate the prayers and support we are receiving from the community, but we need time to grieve and wrap our heads around all of this.”.