Nine soldiers were killed after two U.S. Army Black Hawk helicopters crashed Wednesday night during a training mission in southwestern Kentucky, authorities said.

The HH-60 Black Hawk helicopters from the Army’s 101st Airborne Division crashed around 10 p.m. Wednesday in Trigg County, Kentucky, to the west of the Army base Fort Campbell, the division said in a Thursday statement.

Fort Campbell spokesperson Nondice Thurman confirmed nine soldiers died in the crash.

The 101st Airborne Division, nicknamed the “Screaming Eagles,” is the only air assault division of the U.S. Army.

VISUAL EXPLAINER:US Army Black Hawk helicopters crash in Kentucky leaving nine dead

All nine service members aboard the helicopters were killed during a “multi-ship” exercise using night vision goggles, Brig. Gen. John Lubas, the 101st Airborne deputy commander, said at a news conference Thursday. Five people were in one helicopter and four were in the other, he said.

On Friday, authorities identified the service members killed as Warrant Officer 1 Jeffery Barnes, 33, of Milton, Florida; Cpl. Emilie Marie Eve Bolanos, 23, of Austin, Texas; Chief Warrant Officer 2 Zachary Esparza, 36, of Jackson, Missouri; Sgt. Isaacjohn Gayo, 27, of Los Angeles, California; Staff Sgt. Joshua C. Gore, 25, of Morehead City, North Carolina; Warrant Officer 1 Aaron Healy, 32, of Cape Coral, Florida; Staff Sgt. Taylor Mitchell, 30, of Mountain Brook, Alabama; Chief Warrant Officer 2 Rusten Smith, 32, of Rolla, Missouri; and Sgt. David Solinas Jr., 23, of Oradell, New Jersey.

“This is a time of great sadness for the 101st Airborne Division,” said Maj. Gen. JP McGee, commanding general of the 101st Airborne Division and Fort Campbell. “The loss of these soldiers will reverberate through our formations for years to come.”

Lubas said it was unclear what caused the crash. The Army sent an aviation safety team from Fort Rucker, Alabama, to investigate, according to statement from the 101st Airborne Division.