Now Mark Weaver was on the ground, helping administer CPR, trying to breathe life into Ryan Shay.

"I can't put it out of my mind," Weaver, 42, said. "I think about it a lot. The kid was only 28 years old."

Shay, of Central Lake, Mich., collapsed about 5 1/2 miles into the U.S. Olympic men's marathon trials Saturday in New York City's Central Park. He was pronounced dead at a local hospital about an hour later, at 8:46 a.m., though a cardiologist later told Joe Shay, Ryan's father, that his son probably was dead "before he hit the ground."

An autopsy performed Sunday was inconclusive; Shay's family and his wife, Alicia, are awaiting test results from tissue samples from his heart.

Hundreds of mourners are expected to attend Shay's funeral, 2 p.m. Sunday at Harvest Barn Church in East Jordan. Weaver of Goshen, Ind., plans to be one of them.

He was a volunteer marshal for the race that morning, stationed along a stretch of road near the park's famed Boathouse. Weaver was 50 feet farther up the road from where Shay collapsed.

Before Weaver realized the runner was down, he said he clicked on his stopwatch to begin timing how long it took for the lead pack of runners to complete the first lap of the race.

Initially, from a distance, Weaver didn't think Shay was seriously injured. But once Weaver saw Shay's face, and the "nasty" bruise on the runner's left shoulder, he sprung into action.

Weaver is a former medic.

"There was, basically, three or four of us there at the time — no medical at that point," Weaver said. "But there was a lady there who claimed later to be a doctor. I don't know if she was or not. I never got her name. But she was there and kind of stood over all of us. And there was (another) lady who was doing chest compressions. I was doing the breathing, and there was another gentleman who was there holding his head."

Weaver said, according to his stopwatch, the threesome administered CPR on Shay for 10 minutes, until the police and the ambulance arrived.

"They had a bag on him for a while with oxygen, and I kind of helped out with that a little bit," Weaver said. "They shocked him, and then they put him on a gurney and into the ambulance."

He said the lead vehicle that was fronting the lead pack of runners on the second lap was coming upon the scene just as the ambulance pulled away.

"I just remember thinking, 'Oh, God, how scary that would be to see that ambulance driving away,' " he said. "I thought they all knew something had happened."

Weaver said that he didn't exchange names or phone numbers with the other people who helped Shay. He said he concurs with what a doctor had told Joe Shay. He, too, believes that Ryan Shay "pretty much died instantly."

After Weaver left New York City that weekend, he was stunned that he still had in his coat pocket Ryan Shay's dark Saucony stocking hat that he had worn during the race.

Weaver said he inadvertently placed it in his pocket as they attempted to resuscitate the runner.

On Tuesday, Joe Shay received an email from Weaver, letting him know that he would like to return Ryan's hat to the family.