Two soldiers based at Fort Wainwright in Fairbanks were killed in Iraq when their helicopter crashed during a mission over Mosul, the Department of Defense said today.

Killed were Chief Warrant Officer Donald V. Clark, 37, of Memphis, Tenn., and Chief Warrant Officer Christian P. Humphreys, 28, of Fallon, Nev., the department said.

Both were assigned to the 6th Squadron, 17th Cavalry Regiment, Task Force 49.

The men were flying in an OH-58 Kiowa helicopter Saturday when it went down, said Army spokesman Lt. Col. Jonathan Allen. The Army did not immediately release details on what the mission entailed, but Allen said initially it did not appear they were taking fire.

"There's nothing indicating that they were," Allen said. "They were flying a mission over the Mosul, Iraq, area and they crashed. The cause of that is under investigation."

It was not immediately clear whether Clark and Humphreys were the only two aboard the helicopter, though they were the only two reported to have been killed.

The investigation into the crash could range in duration from weeks to months, Allen said.