Police say a 45-year-old Falls Church man drowned Sunday during a swim race in Reston, Virginia.
Officers and the fire department responded around noon Sunday after a family member had not heard from Kevin Ruby of Falls Church for more than an hour.
Ruby was listed as one of the fastest of 600 swimmers competing in the 31st annual Jim McDonnell Lake Swim, a two-mile race at Lake Audubon.
Ruby finished the first of two laps, police said, but friends became worried when he didn't show up at the end.
"There is a bracelet that all the swimmers have," Fairfax County police Lt. Eli Cory said. "They check with that computer program. It didn't show that he was back."
Crews searched until dark Sunday, with a K-9 out on the boat, while Ruby's friends and family kept vigil at a nearby boathouse. Sonar was used to locate Ruby's body Monday.
The medical examiner will determine the cause of death.
"We don't believe there was any foul play," Cory said. "We have no information to lead us to believe that and we do believe it was possibly a medical emergency."
Dave Hilal, who has competed in 20 triathlons, believes that's what happened.
"There've been studies done where people, they just go into cardiac arrest," he said. "They could be in great shape, but it's such a unique experience you just can't train your body for it."
Ruby had competed in the lake swim events for many years, said Brian Evans, president of the Reston Masters Swim Team, in a statement Tuesday.
"He was a very talented top finisher," Evans said.
Earlier Sunday, Ruby won for his age group in the one-mile race. Evans said that according to police, Ruby may have suffered a medical emergency while competing in the two-mile swim.
"Reston Masters Swim Team (RMST) extends our deepest condolences to the family and friends on the tragic loss of Kevin Ruby," Evans' statement said.
Ruby's death is the second in this race in three years. Another swimmer suffered a heart attack in the race in 2015 and died.
Reston resident Michele Schnitzer said at other times, swimming is prohibited, and she thinks the lake should be reconsidered as a venue for the race.
Ruby practiced at the law firm Portner & Shure for 17 years.
Law firm partner John Portner described him as a skilled and successful litigator who tried cases in Maryland and Virginia.
"Everybody liked this guy," Portner said. "His passion, outside of going to court, was swimming."
Ruby swam in college at Brown University and swam before work every day. He was using the race to prep for the 2018 Bay Swim in June.
He had two young daughters.