Chemical weapons were not used by the U.S. or the other Allies during World War II; however, quantities of such weapons were deployed to Europe for use in case Germany initiated chemical warfare. At least one accident occurred: On the night of December 2, 1943, German Junkers Ju 88 bombers attacked the port of Bari in Southern Italy, sinking several American ships – among them "John Harvey", which was carrying mustard gas. The presence of the gas was highly classified, and authorities ashore had no knowledge of it – which increased the number of fatalities, since physicians, who had no idea that they were dealing with the effects of mustard gas, prescribed treatment not consistent with those suffering from exposure and immersion. According to the U.S. military account, "Sixty-nine deaths were attributed in whole or in part to the mustard gas, most of them American merchant seamen" out of 628 mustard gas military casualties. Civilian casualties were not recorded. The whole affair was kept secret at the time and for many years after the war.