A Serbian athlete died Thursday morning while competing in a CrossFit swimming competition in Texas, the fitness organization said on social media.

"We are devastated by the passing of Lazar Dukic. Our hearts are with Lazar's entire family, friends, and fellow athletes," CrossFit posted on X, formerly Twitter.

Dukic, 28, went underwater and did not resurface during a swimming event Thursday morning at the CrossFit Games, an annual multi-day fitness challenge with athletes from around the world, local media reported.

CrossFit said it was "fully cooperating with authorities and doing everything we can to support the family at this time."

The event was held at Marine Creek Lake in the Texas city of Fort Worth, according to local media.

Dukic was ranked third in Serbia and 88th worldwide, according to his profile on CrossFit's website, which said he had finished first in this year's European CrossFit semi-final.

Events were suspended for the remainder of Thursday, CrossFit said on X, without specifying if the competition would continue as scheduled through Sunday.