Editor's note: This article has been updated with the identity of the victim. 

Denison Police have identified the man found deceased in apartment complex pool Friday morning as John Barnhill, 79. Barnhill was a retired Denison Fire Rescue captain, EMT and paramedic.

Lt. Paul Neumann said officers were dispatched the Creekmore Apartments off Texoma Parkway at approximately 8:30 a.m., after maintenance workers found Barnhill unresponsive in the pool. Neumann said Barnhill was a resident of the complex and that investigators believed he suffered a medical episode related to ongoing health issues while he was in or near the pool. It was unclear when Barnhill entered the pool.

“He worked here from 1963 to 1997 — 34 years,” Denison Fire Marshal John Weda said. “He retired as a fire captain, was still here in town and still stopped by the station to see the people he knew and see how things were going.”

The case remains under investigation by the Denison Police Department. A cause of death has not yet been determined.

Signs seen posted inside the apartment’s pool area Friday morning listed a number of safety rules and warned swimmers that no lifeguard is actively stationed at the pool. Neumann encouraged members of the public to exercise caution whenever they plan to spend time near any pool or body of water.

“Regardless of your age or skill, play it safe and play it smart never go swimming by yourself, and never go to the pool by yourself,” Neumann said.