 While Fanning circled around and dropped a depth charge on the spot where the periscope had been seen , Nicholson , which had raced through the convoy , dropped another in nearly the same location ; both were to good effect . The two depth charges knocked out the electric motor that powered U @-@ 58 's diving planes , making the vessel unmanageable . U @-@ 58 broached the surface momentarily and Fanning dropped another trio of depth charges over the submarine . These three knocked out all electrical power and the manual diving plane controls , which caused the submarine to descend through a depth of 164 ft ( 50 m ) . Amberger ordered the ballast tanks blown and the submarine slowly rose to the surface , stabilizing on the surface with her bow pointing down . The submarines four officers and 35 men evacuated U @-@ 58 and surrendered to Fanning at 16 : 28 , but not before opening the sea valves to allow the U @-@ boat to sink . One of U @-@ 58 's crewmen drowned before reaching Fanning , while another died of a heart attack after he was brought aboard the destroyer . 
