On April 30, 2015, the takeoff of an RC-135V aircraft at Offutt Air Force Base in Nebraska was aborted after a fire broke out in the rear cabin. All 27 crew members exited safely; four were treated for minor smoke inhalation. The fire caused an estimated $62.4 million in damage to the aircraft. An Air Force investigation found that the cause of the mishap was a leak in the high-pressure oxygen system due to poor assembly of the system tubing at depot maintenance. The investigation found that the oxygen leak was caused by the failure of L-3 Communications depot maintenance personnel to tighten a retaining nut connecting a metal oxygen tube to a junction fitting above the galley.