() Four Special Operations soldiers who were aboard the military helicopter that crashed earlier this week near Tacoma, Washington, are believed to be dead, U.S. Army officials said Friday.

The service members, who were not immediately identified, were on a training mission originating from Joint Base Lewis-McChord when their MH-60 Black Hawk helicopter went down in a rural area around 9 p.m. Wednesday. The four soldiers were assigned to the 160th Special Operations Aviation Regiment.

The Thurston County Sheriff’s Department said responding deputies encountered a fire at the crash site.

“Our hearts are with the families, friends, and teammates of these Night Stalkers,” Lt. Gen. Jonathan Braga, commander of the U.S. Army Special Operations Command, said, referring to the regiment’s nickname. “They were elite warriors who embodied the highest values of the Army and the Army Special Operations, and their sacrifice will never be forgotten.” 

He said police, firefighters and personnel from Joint Base Lewis-McChord were conducting recovery efforts. 

“We thank the skilled professionals who are working tirelessly, around the clock to bring our soldiers home,” Braga said in a prepared statement.

An investigation into the cause of the crash continues.