A Fort Hood helicopter on a routine training mission crashed Monday afternoon, killing four crew members, Fort Hood officials said early Tuesday.

The cause of the crash was unknown and will be investigated, officials said.

The crew was assigned to Division West, First Army. Names of the deceased will not be release until 24 hours after next of kin are notified, Fort Hood officials said.

The UH-60 Blackhawk helicopter crashed sometime after 5:49 p.m. Monday in the northeast portion of Fort Hood Range. The crash scene and crew members were found after an extensive search of the area, officials said.

The incident is the latest in a series of crashes involving military Black Hawk helicopters in recent months.