Three Idaho Army National Guard pilots were killed after their helicopter crashed Tuesday night during a routine training mission, the guard said Wednesday.

The pilots were in a UH-60 Black Hawk helicopter when it went down south of Lucky Peak, a park area about 10 miles from Boise, around 8 p.m. Tuesday, the National Guard said in a statement. The bodies were found Wednesday, it said.

The aircraft was last in contact at 7:45 p.m., said Col. Christopher Burt, the Idaho Army National Guard’s state aviation officer. Once an emergency device aboard the aircraft was activated, a team started emergency recovery work that included air and ground search-and-rescue crews, the Guard statement said.

The crews found the aircraft and pilots about 12:15 a.m. Wednesday, it said. The cause of the crash was not known and would be investigated, it said.

The names of those who died were not immediately released.

“This is a tremendous loss to the Idaho National Guard and our community,” said Maj. Gen. Michael J. Garshak, adjutant general of Idaho and commander of the Idaho National Guard. “Our thoughts and prayers are with the families and loved ones as we work through this tragedy.”