A 59-year-old American runner died during the Pikes Peak Marathon despite attempts by competitors to save him some three kilometers from the summit.
Gary Williams died on Sunday while making his way up the 14,115-foot (4,230-meter) mountain in what his son said was his father's 45th marathon.
A rescue helicopter arrived but a paramedic declared him dead. Larry Lewis, search and rescue commander, said Williams most likely died of a heart attack. Williams was about four hours into the race when he collapsed. CPR efforts failed.
Steve Williams said his father had no heart problems, family history of heart trouble or hint of illness before the race. Williams said he and his father had run the Boston Marathon twice.
"He's had high blood pressure as long as I can remember," he told The Gazette. "It's always been controlled by medicine. He was in really great shape."
The death is believed to be the second in the history of the Pikes Peak races, which include a half-marathon called the Ascent. American Bob Love, 57, died during the 1992 Ascent, the AP reports.