Trigger uses an air hose to breathe inside the flooded compartment. He closes the air valve to the stern tube, but finds a second leak, which he can't reach. The crew realizes that Wassner, despite being shackled, is using Morse Code to tap out a signal that the submarine had been captured, so Hirsch kills him. "U-571" surfaces heavily damaged and begins to flood, unable to fire its last torpedo. The pursuing destroyer fires with its main guns: the damage pins Trigger's leg, when he is beyond reach of the air hose. Unable to turn back, he manages to close the valve before he drowns. Tyler orders Tank to fire the torpedo; the destroyer is unable to take evasive action and is sunk. As the crew sigh in relief, Tank reports Trigger's death. However, the submarine has taken severe damage, and so the crew abandons it with the Enigma in their possession. They watch "U-571" as it slips beneath the waves once and for all. They are eventually spotted and rescued from their lifeboat by a US Navy PBY Catalina flying boat.