A U.S. Army helicopter, identified as an AH-64D Apache, crashed near Fort Campbell army base, located on the Kentucky-Tennessee border, approximately 60 miles northwest of Nashville. The crash took place during a routine training excursion, killing two pilots on board the chopper, according to a spokesman for the army base.

The helicopter crashed at approximately 7 p.m. on Wednesday not more than 12 miles south of Fort Campbell, said base spokesman Maj. Allen Hill, according to CBS News.

"Two 101st Airborne Division (Air Assault) pilots were killed when their helicopter crashed near Fort Campbell, Ky., at approximately 7 p.m.," Hill said.

The chopper ended up in a river bottom and was in flames when first responders arrived at the crash site, said Montgomery County Emergency Management Agency Director Jerry Buchanan before adding that the fire had been put out and there were about 30 to 40 emergency workers on site, according to The Tennessean.

The identity of the deceased pilots has not yet been revealed and the cause of the crash is not yet known but the accident is being investigated by the U.S. Army Combat Readiness Center.

Last month, a Black Hawk helicopter crashed at the Fort Hood army base in Texas during a training exercise, killing all four crew members on board, as HNGN previously reported.