Two military helicopters crashed Wednesday night in southwestern Kentucky during a routine training mission, the U.S. Army's Fort Campbell said in a statement.
The status of the crew members was unknown, it added.
The two HH-60 Blackhawk helicopters, part of the 101st Airborne Division, crashed around 10 p.m. Wednesday in Trigg County, Kentucky, according to the statement, which was posted on Facebook.
"The command is currently focused on caring for the servicemembers and their families," the statement said.
Kentucky Governor Andy Beshear wrote on Twitter that "fatalities are expected," adding that police and emergency officials were responding.
The crash is under investigation.