Yet another deadly crash on Friday evening brought the total number of American service members to die during routine aircraft operations last week to seven, as a rash of recent incidents have reignited concerns about the dismal state of readiness the U.S. military has found itself in.

An AH-64E Apache crashed at approximately 9:50 p.m. on Friday night during a training operation at Fort Campbell in Tennessee. Both pilots died in the incident. The Apache and crew belonged to the 101st Combat Aviation Brigade, 101st Airborne Division, though their identities have not yet been revealed to the public. The cause of the crash has also not been revealed, but defense officials claim an investigation is underway.

“This is a day of sadness for Fort Campbell and the 101st Airborne, “ said Brigadier Gen. Todd Royar, acting senior commander of the 101st Airborne Division and Fort Campbell. “Our thoughts and prayer are with the families during this difficult time.”

This crash brought a particularly tragic and deadly week of American military aviation to a close, as seven service members in total lost their lives during non-combat operations. Two Marine Corps CH-53 Super Stallions went down last week, including one incident in Southern California that claimed the lives of four Marines on board. The following day, an Air Force Thunderbird pilot was killed when his F-16 crashed at Nellis Air Force Base in Nevada. Another incident in Djibouti on Tuesday saw a Marine Corps Harrier crash during takeoff, though the pilot  was able to safely eject.