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;[1] 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,[2] and in the immediate aftermath, suspicion centred on one passenger, Albert Voss, who seemingly jumped from the aircraft before it crashed.

[8][9] The subsequent investigation found that the fire had started towards the rear of the plane, in either the lavatory or the luggage area at the back of the cabin.

The investigators narrowed the cause down to the firing of some combustible substance, either accidentally by a passenger or crew member or through vibration or some other natural occurrence, or deliberately by bombing.

Under this theory, Voss sought to escape from the authorities by destroying the aircraft using various flammable substances, to which his work gave him easy access, and then bailing out in the confused circumstances, hoping that in the aftermath no one would notice one fewer body than there should have been.