A Black Hawk helicopter crashed onto a highway Wednesday in the US state of Alabama, killing two members of the Tennessee National Guard who were on board.

The Tennessee National Guard said in a statement that the UH-60 Black Hawk helicopter crashed around 3 p.m. local time (2100GMT) while on a training flight near Highway 53 and Burwell Road in Huntsville.

“We are deeply saddened by the loss of two Tennessee National Guardsmen, and our prayers are with their families during this heartbreaking tragedy,” Brig. Gen. Warner Ross, Tennessee’s Adjutant General, said in the statement.

“We ask Tennesseans to join us in supporting their families during this time of unthinkable grief,” Ross added.

An investigation is taking place, while the Tennessee National Guard said they will support law enforcement and other first responders.