On 13 November, at 15:40, the sonar operator aboard the destroyer Legion detected an unidentified sound, but assumed it was the propellers of a nearby destroyer. One minute later, Ark Royal was struck amidships by a torpedo, between the fuel bunkers and bomb store, and directly below the bridge island. The explosion caused Ark Royal to shake, hurled loaded torpedo-bombers into the air, and killed Able Seaman Edward Mitchell. A 130-by-30-foot (39.6 m × 9.1 m) hole was created on the starboard side and bottom by a torpedo which was judged to have run deep, striking the bilge keel, and detonating inboard of the side protection system. The hit caused flooding of the starboard boiler room, main switchboard, oil tanks, and over 106 feet (32 m) of the ship’s starboard bilge. The starboard power train was knocked out, causing the rear half of the ship to lose power, while communications were severed shipwide.
Immediately after the torpedo strike, Captain Maund attempted to order the engines to full stop, but had to send a runner to the engine room when it was discovered communications were down. The hole in the hull was enlarged by the ship’s motion, and by the time Ark Royal stopped she had taken on water and begun to list to starboard, reaching 18° from centre within 20 minutes. Considering the list of the carrier, as well as the fates of other carriers, including Courageous and Glorious, which had sunk rapidly with heavy loss of life, Maund gave the order to abandon ship. The crew were assembled on the flight deck to determine who would remain on board to save the ship while Legion came alongside to take off the rest. As a result, comprehensive damage control measures were not initiated until 49 minutes after the attack. The flooding spread unchecked, exacerbated by covers and hatches left open during evacuation of lower decks.
Water spread to the centreline boiler room, which started to flood from below, and power was lost shipwide when the boiler uptakes became choked; Ark Royal had no backup diesel generators. About half an hour after the explosion, the carrier appeared to stabilise. Admiral Somerville, determined to save Ark Royal, ordered damage control parties back to the carrier before taking the battleship Malaya to Gibraltar to organise salvage efforts. The damage control parties were able to re-light a boiler, restoring power to the bilge pumps. The destroyer Laforey came alongside to provide power and additional pumps, while Swordfish aircraft from Gibraltar arrived to supplement anti-submarine patrols. The tug Thames arrived from Gibraltar at 20:00 and attached a tow line to Ark Royal, but flooding caused the angle of list to increase rapidly. Water had reached the boiler room fan flat, an uninterrupted compartment running the width of the ship, which forced the shutdown of the restored boiler.
The list reached 20° between 02:05 and 02:30, and when ‘abandon ship’ was declared again at 04:00, had reached 27°. Ark Royal‘s complement had been evacuated to Legion by 04:30; with the exception of Mitchell, there were no fatalities. The 1,487 officers and crew were transported to Gibraltar. The list reached 45° before Ark Royal capsized and sank at 06:19 on 14 November. Witnesses reported the carrier rolling to 90°, where she remained for three minutes before inverting. Ark Royal then broke in two, the aft sinking within a couple of minutes, followed by the bow.