Canandaigua Motorsports Park is a dirt track, where Stewart and other drivers were racing sprint cars.
Michael Messerly, 45, of Batavia, NY was at the track Saturday night, and saw the incident unfold.
"I saw Kevin come out of his vehicle, and I saw him coming down the track, and I thought ‘This guy isn't really going to confront Tony Stewart, is he?'" Messerly said, recounting the incident just hours afterward.
"I picked up Tony Stewart, going into turn one," Messerly said. "I kept looking back and forth between the two of them, until they were close enough in my eye line together.
"And what it appeared to me was Tony picked up a little bit of speed, and then the spot where they were going to intersect, I saw Tony go by, and Kevin Ward wasn't there anymore. Gone."
Messerly was quick to clarify – when he said Stewart "picked up a little bit of speed," he wasn't necessarily saying Stewart was trying to go faster in an attempt to hit Ward.
"It appeared to me that he picked up a little bit of speed to try to avoid the confrontation," Messerly said. "At the same time, with the sprint cars, you often see them hit the gas and let up from the gas. It's just kind of what they do.
"My feeling was, what happened between Tony and Ward, in both incidents – the accident in which Ward ends up in the guard rail, and then the incident in which Ward is struck – I think, in my opinion, both were accidents."
Messerly said he and several of the other fans at the track all were wondering why Ward exited his vehicle.
"Why did he leave the car?" Messerly asked. "I mean, but it's not as if you don't see drivers do it from NASCAR all the way down to the bomber level. People get out of the car to confront other people. But this is a very dangerous sport, and this is very tragic evidence of that."
Someone who claimed to have recorded the accident posted it to YouTube. In the video, you can hear people screaming that Stewart ran over another driver. You can see emergency workers tend to a driver who is laying on the track. The video was taken down after it was reported that Ward had passed away.
Stewart, a long-time driver on NASCAR's Sprint Cup circuit was in New York for Sunday's race at Watkins Glen. Canandaigua Motorsports Park is about 100 miles away from Watkins Glen.
Messerly, who is the publisher of the Batavia Daily News, said he was sitting in the front grandstand with his son Logan, at Canandaigua, near the start-finish line.
"Ward's in a dark fire suit, he's in a black helmet," Messerly said, describing the situation further. "You know, the track, it's a local track, it doesn't have the greatest lighting in the world. But it's a very good track.
"And I just think the circumstances made for a very tragic situation."
"Nothing about that looked to me that there was any intent. … [Tony] raced clean. He was raced clean. It was just a great night of racing that had a tragic ending."
Racing was canceled for the rest of the evening after the accident. Police were dispatched and fans were told to leave the track.
"Tonight's racing events were suspended due to an accident," the track posted on its Facebook page. "Please hold off on any speculation until we have further information to share."
Ontario County Sheriff Phil Povero said that Stewart was "fully cooperative ... He is very upset and confirmed his continuing cooperation" with the investigation.
A spokesperson for Tony Stewart released the following statement, "A tragic accident took place last night during a sprint car race in which Tony Stewart was participating. Tony was unhurt, but a fellow competitor lost his life. Our thoughts and prayers go out to his family and friends. We're still attempting to sort through all the details and we appreciate your understanding during this difficult time."
An autopsy is pending. The local district attorney has been notified. No charges have been filed.
Stewart did not race Sunday. He would have started in 13th place in the lineup at the race at Watkins Glen.