 On 4 December 1942 (St. Barbara's Day), 20 USAAF B-24s of 98 and 376 Squadrons, based in Egypt and armed with 500 and 1000 lb bombs from , flew to Naples unnoticed.Confused with a formation of Ju 52s, and flying apparently from Vesuvio, they were already over the port before anti-aircraft defences opened fire at 16.40.Coming in from the higher terrain around Vesuvio, the pilots had underestimated the time they would need to spot, identify, and target the most important enemy ships before making course corrections that would most successfully result in hitting their primary targets.