The Sinking of the Laconia (2010)

Part one:- In 1942,the Laconia,an old British cruise liner turned troop ship, is returning to Liverpool from Egypt with civilian passengers and Italian prisoners. Its guns are outdated, its captain, Sharp, lost his last ship and the Italians, unhappy at being caged below the water line, are tormented by their Polish guards. Third officer Mortimer learns that his family have been killed in an air raid and seeks comfort with Hilda Smith, a mysterious widow who seems to have visited Germany recently. At that moment the ship is torpedoed by a German U-boat, whose humane captain, Kapitanleutnant Werner Hartenstein, learning that the Laconia was not a warship, decides to rescue the survivors, bringing some into the submarine and towing others in life-boats.