Authorities have identified an off-duty Philadelphia firefighter who died over the weekend while participating in a triathlon.

Dennis McDaniels was found unresponsive in the water Sunday morning while practicing in the Olympics swimming event at the Escape the Cape Triathlon in North Cape May.

McDaniels was taken to the hospital, where he was pronounced dead. A cause of death has not yet been announced.

The 36-year-old firefighter was a 12-year veteran and was recently assigned to Ladder 15, according to a report by the Philadelphia Inquirer. He was a married father of four.