On 30 December 1917 under the command of Oberleutnant zur See Horst Obermüller, UC-34 torpedoed the British troop ship off the Port of Alexandria. Aragon's escort, the destroyer HMS Attack, rescued 300 to 400 survivors but then UC-34 torpedoed and sank her was well. Of 2,500 personnel who had been aboard Aragon, 610 were killed. UC-34 was scuttled at Pola on 28 October 1918 on the surrender of Austria-Hungary.