FORT WORTH, Texas (AP) — A competitor in the CrossFit Games has died while competing in a swimming event Thursday morning on a Texas lake.

CrossFit CEO Don Faul said during a news conference that they were "deeply saddened" by the death of one of their athletes at Marine Creek Lake in Fort Worth, and they were working with authorities on the investigation into the death.

The Tarrant County medical examiner's office identified the athlete as 28-year-old Lazar Dukic of Serbia. The medical examiner's office had not yet listed his cause of death.

An official with the Fort Worth Fire Department said they got called out around 8 a.m. to assist police because there "was a participant in the water that was down and hadn't been seen in some point in time."

He said they responded for search and rescue and were not on the scene when the initial call was made. He said the athlete's body was found about an hour later.

Faul said CrossFit did have safety personnel on site at the event.

Faul said the CrossFit community is like a family. "We're doing everything in our power during this tragic time to support the family, to support our community," Faul said.

The mission of the CrossFit Games, first held in 2007, is to "find the fittest athletes in the world," the CrossFit website said. It says the games change every year and often the details are not announced until just before the event.

Dukic's biography on the CrossFit website says he was the third-ranked CrossFit athlete in Serbia and the 88th-ranked worldwide.