FORT WORTH (CBSDFW.COM) – A participant in the annual Original Mud Run event slipped while traversing the Trinity River and was pulled under and died, Fort Worth Fire Dept. spokesman Timothy Hardeman said.

The event was held at LaGrave Field and the man was reported missing after the event was finished on Saturday. Fort Worth Police and Fire departments filed a missing persons report and began searching, but had to call it off a few hours later at nightfall, Hardeman said.

The man’s body was found at 10:54 a.m. Sunday in the Trinity River. Hardeman said the man’s friends and family were present after the race. He has not been identified nor has a cause of death been announced.

“Currently we are making ourselves available to assist the family in any way we can with their grief,” a Mud Run spokesperson said in an email. “Safety is paramount in our events and we are profoundly saddened by the loss of one of our participants.”

The spokesperson promised to issue a more formal statement on Monday and declined to be identified when asked.

Hardeman said it took divers about 15 minutes to recover the man’s body after a brief storm delay.

“Our divers are used to working in this environment. This is part of what they train on, the Trinity River,” he said. “Again, the weather played a part in when we could get into the water.”

The Original Mud Run is annual military-style obstacle course where participants run, swim, climb and pull themselves along a 5 kilometer course or a 10 kilometer one, according to its website.

Obstacles include a simulated mine field, a rope swing, walking along logs and crawling through a mud pit. This is the event’s 15th year. YouTube video shows participants swimming across the Trinity. They can take part individually or with a team.

The event’s site urges participants to consult their doctor beforehand.

“Although none of the obstacles are impossible or dangerous, they do require a certain level of strength and fitness and the potential exists for injury due to falls, trips and crawling,” the Original Mud Run’s website warns.

The site says volunteers served as safety monitors throughout the course.