The Defense Department announced five Marines died after an MV-22B Osprey tiltrotor aircraft crashed in California on June 8.

The Marines were with Marine Aircraft Group (MAG) 39, 3rd Marine Aircraft Wing (MAW) and had an “aviation mishap” during a training mission near Glamis, Calif. The aircraft is based with MAG 39 at Marine Corps Air Station Camp Pendleton, Calif.

“We mourn the loss of our Marines in this tragic mishap. Our hearts go out to their families and friends as they cope with this tragedy,” Maj. Gen. Bradford Gering, commanding general of 3rd MAW, said in a statement.

The Marine Corps said the identities of the service members would not be released until 24 hours after all next-of-kin notifications are finished. It also said equipment recovery efforts have started and an investigation is underway.

“While military service is inherently dangerous, the loss of life is always difficult. 3rd Marine Aircraft Wing is committed to providing support to the families, friends, and fellow service members of the fallen Marines,” the service added.

The service also noted that unlike some initial social media and news reports, no nuclear materials were on board the aircraft.

This comes after an F/A-18E Super Hornet pilot died in a crash near Trona, Calif., on June 3. That aircraft was based at Naval Air Station Lemoore, Calif. (Defense Daily, June 6). Another Super Hornet crashed in a remote area of Death Valley National Park, Calif. In October, where the pilot survived with minor injuries (Defense Daily, Oct. 8, 2021).

Previously, in March four Marines died in an OV-22B Osprey crash during a training mission in Norway, assigned to Medium Tiltrotor Squadron (VMM) 261 based at Marine Corps Air Station New River, N.C.

The Osprey is built by a consortium consisting of Bell [TXT] and Boeing [BA].