On 29 August 2007, six AGM-129 ACM cruise missiles, each loaded with a W80-1 variable yield nuclear warhead, were mistakenly loaded onto a United States Air Force (USAF) B-52H heavy bomber at Minot Air Force Base in North Dakota and transported to Barksdale Air Force Base in Louisiana. The nuclear warheads in the missiles were supposed to have been removed before the missiles were taken from their storage bunker. The missiles with the nuclear warheads were not reported missing, and remained mounted to the aircraft at both Minot and Barksdale for 36 hours. During this period, the warheads were not protected by the various mandatory security precautions for nuclear weapons.