According to the Woodlands Fire Department, crews responded to Northshore Park, located at 2505 Lake Woodlands Dr., at about 7:30 a.m. on Saturday after a call about a lost swimmer in the lake.
Authorities said that multiple boats were used in the search for the victim, including a boat with side-scan sonar, which helps search the water during low-visibility conditions. At about 8 a.m., the sonar "detected a target," and it was later determined to be the victim, who had sunk about 10 feet, according to officials.
Officials said the North Montgomery County Dive Team was called to assist in the recovery of the victim. First responders said they recovered the victim at about 9:40 a.m., who was then pronounced dead at the scene.
The victim's body was taken to the medical examiner, according to authorities, with the identity of the victim still unknown.
Authorities explained that swimming is normally not allowed in Lake Woodlands due to the "zero visibility" in the water, with exceptions made for some special events. Officials said there was a large number of people in the water at the time, with support watercraft nearby who were able to assist quickly.
In a social media post, Ironman officials confirmed the victim was a participant in Saturday's triathlon, with the incident occurring during the swimming portion of the race.
The Montgomery County Sheriff's Office said it was notified of the drowning and is currently investigating the incident.
An athlete died during the same competition, also while swimming in Lake Woodlands, in 2017. At that time, spectators said multiple people tried to resuscitate Glen Bruemmer, 54, who became unresponsive while competing.