(Fort Campbell) A crash involving two US Army helicopters killed nine people late Wednesday night in Kentucky.

The crash happened around 10 p.m. local time during routine training. Two HH-60 Black Hawk helicopters from the famed 101st Airborne Division were involved.

The crash happened in Trigg County, about 30 miles northwest of the town of Fort Campbell.

Fort Campbell is near the Tennessee border, about 100 miles northwest of Nashville.

A witness told the local press that he saw two helicopters flying very close to each other before the accident. A gigantic explosion occurred about a minute later.

The investigation is continuing.