Madison firefighter is second person to die after swimming on Lake Monona for Ironman triathlon

A Madison firefighter on Tuesday became the second person to die after the swimming portion of a triathlon on Lake Monona, authorities said.

Todd Mahoney, a 38-year-old firefighter with the Madison Fire Department, was found unresponsive in the water Sunday morning during the Ironman 70.3 Wisconsin triathlon and was in critical condition until Tuesday, when he died, fire officials said.

About an hour earlier, Michael McCulloch, 61, of Cottage Grove was found unresponsive in the water. Paramedics took him to a hospital, where he was pronounced dead. Preliminary autopsy results indicate McCulloch died from an apparent accidental drowning.

The Dane County medical examiner’s office said preliminary autopsy results confirm that McCulloch’s death “was consistent with an accidental drowning due in part to a medical event.”

Mahoney served for nine years with the department and was previously a paramedic. He is survived by his wife and three young sons, the fire department said.

The medical examiner’s office is still investigating the cause of Mahoney’s death. 

A fire department spokeswoman previously said it’s possible both men may have suffered medical emergencies that caused them to go underwater.

The Ironman 70.3 race — also known as a ‘half-Ironman’— it is half the distance of an Ironman triathlon. Athletes swim 1.2 miles, bike 56 miles and run 13.1 miles.

Mahoney is the second Wisconsin firefighter to die within a month, and the third high-profile death within a year. Mitchell F. Lundgaard of Appleton was shot to death May 15 at the Valley Transit Center during a medical call. And Sun Prairie firefighter Cory Barr died after a gas main explosion leveled the bar he owned.

The Associated Press contributed to this report.

Contact Sophie Carson at (414) 223-5512 or scarson@gannett.com. Follow her on Twitter at @SCarson_News.