An Idaho doctor suffered a possible cardiac arrest during the swimming portion of the 11th Annual Emmett's Most Excellent Triathlon on Saturday, around 9:45 a.m.
Dr. Matthew Sell was a neonatal and perinatal specialist at Saint Alphonsus hospital in Boise. The 58-year-old was pulled from the waters of Blacks Canyon Reservoir during the competition, according to race officials.
He had no pulse when lifeguards found him, and was declared dead after he was transported to a hospital in Boise.
Officials said the full contingent of safety crews required by United States Triathlon were on hand.