One of two Navy SEALs injured during parachute training in southern Arizona has died while the other man remained hospitalized Friday, authorities said.

The names of the two SEALs, both from an East Coast Naval Special Warfare Unit, weren't immediately released and military officials said the accident was under investigation.

U.S. Special Operations Command spokesman Kenneth McGraw said the SEALs were practicing "routine military free-fall training" when the accident occurred about 12:30 p.m. MST Thursday.

Pinal County Sheriff's officials said the injured men collided in mid-air and landed in separate areas.

The Department of Defense said an E-8-Senior Chief was taken to University of Arizona Medical Center, where he was pronounced dead.

The other SEAL _ an E-6 Petty Officer First Class _ was in stable condition at the same Tucson hospital, military officials said Friday.

The command has a parachute testing and training facility at the Pinal Airpark in Marana, according to McGraw, who added that training programs are operated there year-round.

The area is in rugged desert terrain northeast of Tucson.