Top distance runner Ryan Shay died during the US men's Olympic marathon trials on Saturday after collapsing about 9km into the race. He was 28.
Shay was taken to Lenox Hill Hospital and was pronounced dead, New York Road Runners president Mary Wittenberg said.
"It cuts a knife through everybody's hearts," said Wittenberg, whose group organized the race.
She said Shay received immediate medical attention. The medical examiner's office said an autopsy was to be performed yesterday.
"There were several layers of medical response. It was very quick," said Wittenberg, who would not elaborate on what steps were taken.
Shay's father, Joe, said his son was first diagnosed with a larger than normal heart at age 14.
Joe Shay said his son was cleared for running this spring by doctors but was told he might need a pacemaker when he is older.
Years ago, after a car accident as a 16-year-old, Joe Shay said doctors re-evaluated Ryan's heart and determined it had gotten even larger. Each time, he said, they believed it was because Ryan was a runner.
"But he never complained about it," Joe Shay said.
Shay of Flagstaff, Arizona, hit the ground near the Central Park boathouse, a popular Manhattan tourist spot, during the 26.2-mile (42.1km) qualifier for the Beijing Games. The death came a day before the New York City Marathon, when millions usually line the streets in one of the sport's showcase days.
"He was a tremendous champion who was here today to pursue his dreams," said Craig Masback, chief executive of US track and field's governing body. "The Olympic trials is traditionally a day of celebration, but we are heartbroken."
Shay was a favorite going into the 2004 trials but was hampered by a hamstring strain and finished 23rd. He was the 2003 US marathon champion and was third at this year's US 25K championships. He also won the US half marathon in 2003 and 2004. He was the US College 10,000m champion in 2001, the first national individual title in track for Notre Dame.
Shay was the US 20,000m (20K) road racing champion in 2004, making him a four-time national champion.
His wife, Alicia, also is a top distance runner. She was a two-time college champion and the collegiate 10,000m record-holder while running as Alicia Craig at Stanford. She and Ryan met at the 2005 NYC Marathon and they married in July. Alicia was hoping to make it to Beijing in the women's 10,000m.
"My thoughts and prayers just go out to them and their family," said winner Ryan Hall, a college teammate of Alicia's at Stanford.
Shay, who was born in Michigan and graduated from Notre Dame, qualified for the trials at last year's Twin Cities Marathon.
Before the race, Shay said during a conference call he had moved from Mammoth Lakes, California, where he had been training with Team Running USA, to Flagstaff, where he was training at the Center For High Altitude Training.
"It's a big loss for the running community," said 2004 women's marathon Olympic bronze medalist Deena Kastor, who once trained with Shay. "It's a day we should be celebrating. It has cast a pall. The distance running community is very close."