A Navy SEAL accident in Arizona left one dead and another injured Thursday during parachute training at Pinal Airpark, Arizona.

A U.S. Special Operations Command official said Friday the SELA died in at the University of Arizona Hospital Thursday and the other SEAL is in stable condition, according to USA Today. SEALS were doing "routine military free-fall training" according to Kenneth McGraw, a spokesman for U.S. Special Operations Command.

Pinal County Sheriff's officials say the injured men collided in mid-air and landed in separate areas, and the accident is under investigation.

The Department of Defense said a Senior Chief Petty Officer was the senior enlisted officer that died. He was a member of the Navy's Special Warfare Development Group, better known as Seal Team Six, NBC reports.

The tragedy follows an accident at Pinal Airpark in 2008, when two Virginia Beach-based Navy SEALS died a month apart in similar parachute incidents. Just two weeks earlier seven Marines were killed after a mortar round exploded inside the tube during a training exercise in Nevada.