On 17 August 1943, US Army Air Forces launched strategic bombing raids on the German cities of Schweinfurt and Regensburg with 376 B-17 bombers without long-range fighter escorts. The mission inflicted heavy damage on the Regensburg target but lost 60 bombers, or 16% of the force, with another 58–95 heavily damaged and a loss of 564 airmen killed, missing or captured. A second raid on 14 October with 291 bombers damaged ball bearing factories, halting production for six weeks, but resulted in the loss of 77 bombers, or approximately 26%, with damage to 121 more and 655 airmen killed or captured. Unescorted daylight bomber raids deep into Germany were suspended until February 1944.