Two U.S. Army helicopters collided in flight Thursday in Alaska while returning from a training mission, killing three soldiers and injuring a fourth, the Army said.

Two of the soldiers died at the crash site near Healy, Alaska, and a third died on the way to a hospital in Fairbanks. A fourth soldier was being treated at a hospital for injuries, the Army said in a statement Thursday. Additional information was not immediately available Friday.

The names of those killed were being withheld until relatives could be notified, the Army said.

The Army said the cause of the crash was under investigation and that more details would be released when they become available. A team from Fort Novosel, Alabama, will conduct the investigation, the Army said.... Read More: Associated Press