A US Army MH-60 Black Hawk helicopter operated by the elite 160th Special Operations Aviation Regiment crashed in a wooded area of the Colorado foothills west of Denver on Tuesday, with four people aboard.

The helicopter, based at Fort Campbell, Kentucky, and operated by the Army’s “Night Stalkers,” went down on the eastern side of Thorodin Mountain in Gilpin County, north of Golden Gate Canyon State Park.

The crash occurred shortly before 11:30 a.m. local time during a routine training exercise. Emergency crews responded to the remote, rugged site in the Roosevelt National Forest.

The Gilpin County Sheriff’s Office said all four people aboard the aircraft were accounted for and that no injuries had been reported.

“At this time, no injuries have been reported, and there is no reported fuel leak or fire associated with the incident,” the sheriff’s office said.

It added that emergency personnel remained at the scene and that there was no known threat to the surrounding community.

Aerial footage from the crash site showed significant damage to the helicopter’s main rotor blades, which appeared to have snapped, while the fuselage remained largely intact.

The US Army Special Operations Aviation Command described the incident as an “aviation mishap.”