Vanoc spotted the surfaced U-99 , and both destroyers opened fire on the stricken U-boat , which was scuttled by her crew as they abandoned ship .
Walker picked up U-99 on her sonar and attacked with depth charges , forcing the submarine to the surface .
Vanoc spotted the surfaced U-99 , and both destroyers opened fire on the stricken U-boat , which was scuttled by U-99 's crew as they abandoned ship .
Walker picked up U-99 on her sonar and attacked with depth charges , forcing the submarine to the surface .