(CNN) Two men died following an Ironman 70.3 triathlon in Madison, Wisconsin, over the weekend, the Madison Fire Department said.

Todd Mahoney, 38, an apparatus engineer with the fire department, and Michael McCulloch, 61, of Cottage Grove, Wisconsin, both died during the swimming portion of the lengthy race.

The Ironman 70.3 is a three-part race, with a 1.2-mile swim, 56-mile bike ride and a 13.1-mile run.

Competitors began swimming in heats, starting at 7 a.m. Sunday, according to the Ironman website

McCulloch was rescued from Lake Monona by the Madison Fire Department, taken to the hospital and later pronounced dead, a fire department statement said.

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