After an on-board fire that may have been the first incident of airliner sabotage, the Imperial Airways biplane City of Liverpool broke apart in mid-air, killing fifteen people.

Imperial Airways was an early British commercial long-range airline, operating from 1924 to 1939 and principally serving the British Empire routes to South Africa, India, Australia and the Far East, including Malaya and Hong Kong. Passengers were typically businessmen or colonial administrators, and most flights carried about 20 passengers or fewer. Accidents were frequent: in the first six years, 32 people died in seven incidents. Imperial Airways never achieved the levels of technological innovation of its competitors and was merged into the British Overseas Airways Corporation (BOAC) in 1939. BOAC in turn merged with the British European Airways (BEA) in 1974 to form British Airways.

On 28 March 1933, an Armstrong Whitworth Argosy II passenger aircraft, named City of Liverpool and operated by British airline Imperial Airways, crashed near Diksmuide, Belgium, after suffering an onboard fire; all fifteen people aboard were killed, making it the deadliest accident in the history of British civil aviation to that time. It has been suggested that this was the first airliner ever lost to sabotage, and in the immediate aftermath, suspicion centred on one passenger, Albert Voss, who seemingly jumped from the aircraft before it crashed.