A production line was nearly ready at Peenemünde when the Operation Hydra attack occurred. The main targets of the attack included the test stands, the development works, the Pre-Production Works, the settlement where the scientists and technicians lived, the Trassenheide camp, and the harbor sector. According to Dornberger, "Serious damage to the works, contrary to first impressions, was surprisingly small." Work resumed after a delay of four to six weeks, and because of camouflage to mimic complete destruction, there were no more raids over the next nine months. The raid resulted in 735 lives lost, with heavy losses at Trassenheide, while 178 were killed in the settlement, including Dr. Thiel, his family, and Chief Engineer Walther. The Germans eventually moved production to the underground "Mittelwerk" in the Kohnstein where 5,200 V-2 rockets were built with the use of forced labour.