How a devastating air raid on the Italian port of Bari during World War Two led to the deadly release of mustard gas. Winston Churchill ordered the incident to be kept secret for years. We hear from Peter Bickmore BEM, who was injured during the raid. (Photo: Seventeen Allied ships go up in flames in Bari, Italy, after a raid by German bombers on 2 December 1943. Credit: Keystone/Getty Images)