Apr. 28—The U.S. Army is beginning an investigation into the crash of two Apache helicopters in Interior Alaska Thursday after the military aircraft collided near Healy returning from a training mission.

The crash killed three soldiers and injured one who was transported to a Fairbanks hospital for treatment.

Both AH-64 Apache helicopters had two soldiers on board — all from the 11th Airborne Division's 1st Attack Reconnaissance Battalion, 25th Aviation Regiment at Fort Wainwright in the Fairbanks area, Army officials said.

Two of the soldiers were declared dead at the scene, the 11th Airborne Division said in a statement Thursday evening, and a third died while being taken to a Fairbanks hospital.

It wasn't immediately clear what may have caused the crash, which is being investigated by a team from the Army Combat Readiness Center at Fort Novosel in Alabama, officials say.

On Friday, the unit involved in the crash was standing down to allow members to cope with the aftermath, according to John Pennell, a spokesman for U.S. Army Alaska.

"Unit leadership is meeting with all of its its personnel and their families at Fort Wainwright," Pennell said. "They're kind of beginning the grieving process and ... explaining what resources are available to the families going forward."

The investigation that's just getting underway will determine more details about the circumstances surrounding the crash, he said.

The Emergency Assistance Center at Fort Wainwright, reachable at 907-353-4452, has been activated "to provide support for families, friends and fellow soldiers of those involved in the crash," Army officials said Thursday.

Several Alaska National Guard aircraft responded to the area following word of a possible crash early Thursday afternoon, Guard spokesman Alan Brown said Friday. A KC-135 Stratotanker in the area for an unrelated training exercise out of Eielson Air Force Base broke off and headed to the suspected crash site to help relay information, Brown said.

Then, after the U.S. Army Alaska's official notification of the crash came in, the Guard launched two combat search and rescue aircraft within an hour, he said: An HH-60 Pavehawk helicopter with a team of pararescuemen, and an HC-130 tanker.

The Federal Aviation Administration issued a temporary flight restriction for skies around the crash area Thursday afternoon through next week to "provide a safe environment for rescue."

Healy is about 100 road miles south of Fairbanks, and about 250 miles north of Anchorage.

There have been three U.S. military helicopter crashes and a rollover recorded so far this year, in Alabama, Kentucky and Alaska, according to the Associated Press. Military officials are still investigating the causes of the crashes, which involved Black Hawk or Apache helicopters. A total of 14 soldiers have died and three have been injured, all in training missions.

In February, an AH-64 Apache helicopter crashed during takeoff after it stopped to refuel at the Talkeetna Airport, injuring two soldiers. That aircraft was part of a group of four Apache helicopters traveling from Fort Wainwright to Joint Base Elmendorf-Richardson for training.

In March, nine soldiers were killed in Kentucky when two Army Black Hawk helicopters crashed while conducting a nighttime training exercise.

This is a developing story. Check back for updates.