During World War II the United States was prepared to use poison gas against the German army. 100 tons of mustard gas were shipped to the port of Bari in southern Italy, held by the Allies and far behind the front lines, on the ammunition ship John Harvey. Being an ammunition ship, the John Harvey also carried a full load of conventional explosive munitions. Disaster At Bari tells the story of how, on the night of December 2, 1943, the port of Bari was attacked by 105 Ju 88 Luftwaffe bombers. The attackers achieved complete surprise: the Allied high command did not think the Luftwaffe was still capable of a raid this far behind the front lines. The lights were on in the harbor so that unloading the docked ships could continue during the night. The Luftwaffe pilots and bombardiers made good use of this, and sank 17 cargo and transport ships, with 8 others damaged. One of the targets was the John Harvey. As an ammunition ship it blew up in a huge explosion, spreading mustard gas all around.

Hundreds of victims were taken to hospitals with strange symptoms. Many died and the medical staff had no idea why. The presence of mustard gas on the John Harvey was a closely guarded secret. Eventually a senior medical officer was flown in from Allied headquarters in Algiers. He quickly realized that the men had been exposed to mustard gas. With some difficulty, he was able find out that the John Harvey had mustard gas in its cargo. There 617 military and merchant marine mustard-gas casualities that night. 84 men died. No one knows about the casualties among the Italian civilians. Many lives could have been saved if the presence of mustard gas had been known immediately and proper treatment administered to the victims.