In response to this threat, the U.S. Navy conducted Operation Teardrop between April and May 1945 to sink German U-boats detected heading for the Eastern Seaboard, which were believed to be armed with V-1s or V-2s. Five of the seven Type IX submarines that stationed off the U.S. were sunk; four with their entire crews. Thirty-three crew members were captured. Following the end of the war in Europe, the submarines , "U-805", "U-858" and surrendered at sea before returning to bases on the U.S. east coast.