An airman stationed at Kadena Air Base in Japan died in his off-base residence last week.

Tech. Sgt. Don Sardin was found on Tuesday, according to Stars and Stripes.

Sardin was assigned to the 1st Special Operations Squadron, 353rd Special Operations Group. The squadron operates the MC-130 Combat Talon II aircraft.

The cause of death hasn’t been determined, but Stars and Stripes reported that foul play isn’t suspected.

“It is never easy to say goodbye to a fellow Air Commando,” Col. Kenneth McAdams, the group’s deputy commander, said in a statement. “We will all miss Don dearly. He dedicated his life to the service of his nation.”

The incident is under investigation.