Two pilots were killed after their AH-64D Apache crashed during a training exercise near Fort Campbell in Tennessee on Wednesday. Fort Campbell spokesman Maj. Allen Hill confirmed the deaths early Thursday, adding that the two-person helicopter of the 101st Combat Aviation Brigade went down during “routine training,” just 12 miles south of Fort Campbell in Montgomery County. The cause of the accident is still unclear and the U.S. Army Combat Readiness Center was still investigating the crash, according to a press release. The two pilots have not been named, pending notification of kin. The crash is one of at least three Army helicopter crashes that have happened during training in the last month.