Two pilots were killed Saturday when a Tennessee National Guard helicopter crashed near Caryville in Campbell County, Tenn.

The pair were conducting a routine training flight when their OH-58D Kiowa Warrior aircraft crashed at about 5:30pm local time, according to Maj. Randy Harris, director of Joint Public Affairs for the Tennessee Military Department. The cause of the crash was not immediately known.

The names of the pilots were withheld pending notification of their next-of-kin.

The Tennessean reported the helicopter had crashed in the woods near the Royal Blue Recreation area, about 30 miles (48km) north of Knoxville, and there was currently no access to the site.

The crash downed several power lines, leaving more than 5,000 households without electricity for a couple of hours.