The Air Force says Tech Sergeant David Gressett collapsed Thursday while inside an altitude chamber.
The chamber is used to help aircrews recognize hypoxia, which is a decrease in oxygen going to tissue. It can be a problem for AC-130 gunship crewmen, such as Gressett.
Officials say there were others in the chamber when Gressett collapsed. He was taken to Bay Medical Center, where he was pronounced dead.
Gressett was assigned to the 16th Special Operations Wing at nearby Hurlburt Field. He’d been stationed there for the past ten years.
Authorities say they can't remember a similar accident in 50 years of training at Tyndall, which is just east of Panama City.