Two soldiers were killed when their helicopter crashed during a training mission at Fort Campbell, officials at the Army post said Saturday.

The AH-64E Apache helicopter crashed Friday night in a training area at the sprawling Army post that straddles the Kentucky-Tennessee line, Fort Campbell officials said.

"This is a day of sadness for Fort Campbell and the 101st Airborne," said Brig. Gen. Todd Royar, acting senior commander of the 101st Airborne Division and Fort Campbell. "Our thoughts and prayers are with the families during this difficult time."

The soldiers' names were not immediately released pending notification of their families. They were members of the 101st Combat Aviation Brigade, 101st Airborne Division (Air Assault), Fort Campbell said.

They were the only two people aboard the helicopter, post officials said.

The crash occurred at about 9:50 p.m. Friday. The cause is under investigation.