Two U.S. Army helicopters returning from a training flight crashed in Alaska on Thursday with four people aboard, killing three soldiers and injuring the fourth, Army officials said.

The Army’s 11th Airborne Division confirmed the deaths late Thursday, saying that the two AH-64 Apache helicopters had crashed near Healy, Alaska, which is more than 200 miles north of Anchorage. Two of the four soldiers were declared dead at the crash site, and a third died on the way to a hospital in Fairbanks, it said.

“This is an incredible loss for these soldiers’ families, their fellow soldiers, and for the division,” Maj. Gen. Brian Eifler, the division’s commanding general, said in a statement.

The Army said it was withholding the names of the dead until their families could be notified, and that the incident was under investigation. John M. Pennell, a spokesman for 11th Airborne Division, said that he did not yet have details on the injured soldier’s condition.