US aircrews claimed more than 500 German fighters destroyed, though the numbers were massively exaggerated. The Luftwaffe losses were high amongst their twin-engined "Zerstörer" units, and the Bf 110 and Me 410 groups were severely depleted. More worrying for the Jagdwaffe (fighter force) than the loss of 355 aircraft was the loss of nearly 100 pilots (14 percent) who had been killed. In contrast to the raids of the previous year, the US losses were replaceable, while the Germans were already hard pressed due to the war in the East. Although not fatal, Big Week was an extremely worrying development for the Germans.