On 23 September 1983, Fleming was involved in the Maze Prison escape, the largest break-out of prisoners in Europe since World War II and in British prison history. Fleming, along with 37 other republican prisoners, armed with 6 hand-guns, hijacked a prison meals lorry and smashed their way out of HMP Maze past 40 prison wardens and 28 alarm systems. During the escape Gerry Kelly shot and injured a prison warden as the officer attempted to foil the escape.