Organizers of the event have released a statement.
An Ironman race in Alberta ended in tragedy over the weekend after one of its athletes drowned during the competition.
Organizers of the Ironman 70.3 Calgary triathlon said their safety personnel were alerted to an athlete in distress during the swimming part of the race on Sunday, August 1.
Officials were called to Harmony Lake, where competitors were required to complete a 1.9-kilometre swim, but despite the efforts of volunteers and emergency medical staff, the 47-year-old man from Ontario was pronounced dead at the scene.
In a statement posted to the event's Facebook page, organizers said they were "incredibly saddened" to confirm the death of the athlete.
They added: "We share our greatest sympathies with the family and friends of the athlete and will continue to offer them our support as they go through this very difficult time. We thank the swim safety personnel and first responders who worked quickly to provide the athlete with medical support."
The RCMP has not confirmed the identity of the man, but they say his next of kin have been notified.
Triathlon Canada also posted to their social media channels following the incident.
A spokesperson said: "We are deeply saddened to hear of the passing of a race participant in our community at the Ironman Calgary 70.3 on August 1. Our deepest sympathies go out to the athlete's family and friends, and the local organizing committee."