HMAS SYDNEY AND THE KORMORAN ENGAGEMENT

On the afternoon of 19 November 1941, Sydney was off the coast of Western Australia, near Carnarvon, and heading south towards Fremantle. Around 1555, the cruiser spotted a merchant ship on a northbound course, which quickly turned away from the coast at 14 knots. Sydney increased speed to 25 knots and made to intercept. As she closed the gap, Sydney began to signal the unidentified merchantman, first by signal light, then after no reply was forthcoming and the distance between the two ships had decreased, by a combination of light and signal flag. The merchant ship hoisted her callsign, but as she was ahead and just port of Sydney, the flags were obscured by the funnel. A request from the cruiser that the merchant ship make her signal letters clear, which the signals officer did by lengthening the halyard and swinging the flags clear. The callsign was that of the Dutch ship Straat Malakka, but she was not on Sydney‍ '​s list of ships meant to be in the area.  Further flag signals were exchanged between the ships, with Sydney asking the Dutch ship's destination and cargo.

At 1700, a distress signal was transmitted by Straat Malakka, indicating that she was being pursued by a merchant raider. Following this, Sydney pulled alongside the merchant ship from astern; pacing the merchantman on a parallel course, approximately 4,300 ft away. Sydney‍ '​s main guns and port torpedo launcher were trained on the ship. Fifteen minutes later, at around 1730, Sydney sent a signal ordering her to show the secret callsign. Straat Malakka had not replied because she was the German auxiliary cruiser Kormoran in disguise, and when asked to reveal a callsign the Germans did not know, they responded by de-camouflaging and opened fire.  Prompted by the raider's unveiling, Sydney also fired, but while her first salvo either missed or passed through Kormoran‍ '​s upper superstructure with minimal damage, four of the raider's six 5.9 ins guns were able to destroy the cruiser's bridge and gun director tower, damage the forward turrets, and set the aircraft on fire. Sydney did not fire again until after the raider's sixth salvo: "Y" turret fired without effect, but "X" turret was able to put multiple shells into Kormoran, damaging machinery spaces and one of the raider's guns, while igniting an oil tank. During this, Kormoran maintained heavy fire, and around the time of the eighth or ninth German salvo, a torpedo launched at the start of the engagement hit Sydney just forward of "A" turret and near the Asdic compartment, the weakest point on the ship's hull, ripping a hole in the side and causing the bow of the cruiser to angle down. Down by the bows, the cruiser swung hard to port, and passed behind Kormoran; during the turn, shells from the raider knocked "B" turret off Sydney.

By 1735, Sydney was heading south and losing speed, wreathed in smoke from multiple fires. Her main armament was disabled and her secondary guns were out of effective range. The cruiser continued to be hit by shells from Kormoran‍ '​s aft guns as the distance between the ships increased. The Germans reported that around 1745, all four torpedoes from Sydney‍ '​s starboard launcher were fired, but as Kormoran was manoeuvring to bring her port broadside to bear, they all missed. In fact, only two torpedoes from Sydney‍ '​s port launcher were ever fired, which must have happened some time earlier. The raider's engines broke down after this turn, but she continued to fire on Sydney at a high rate despite being immobilised, although many of the shells would have missed as the distance between the two ships increased. Kormoran ceased fire at 1750, with the range at 6,600 yards, and launched another torpedo at 1800, but missed Sydney.

The Australian cruiser continued on a south-south-east heading at low speed; observers aboard Kormoran doubted that Sydney was under control. Although disappearing over the horizon shortly later, the glow from the damaged, burning warship was consistently seen by the Germans until about 2200, and sporadically until midnight. At some point during the night, Sydney lost buoyancy and sank: the bow was torn off as she submerged and descended almost vertically, while the rest of the hull glided 1,600 ft forward as she sank, hitting the bottom upright and stern first. Sydney‍ '​s shells had crippled Kormoran; the German sailors abandoned ship after it was determined that below-deck fires could not be controlled before they reached the gun magazines or the mines in the cargo hold. The raider was scuttled at midnight, and sank slowly until the mine deck exploded half an hour later. 

 Sydney‍ '​s failure to reach Fremantle on 20 November was not initially cause for concern, as several factors might have delayed the cruiser, none of which were sufficient reason to break the order to maintain radio silence. However, with no sign of the cruiser by 23 November, shore-based wireless stations began transmitting orders for Sydney to break silence and report in. A raft of German survivors was recovered by a British tanker on 24 November, at which point a large-scale air and sea search began.  During this search, which lasted until the evening of 29 November, 318 survivors from Kormoran‍ '​s 399 personnel were found, but apart from a Carley Float and a lifebelt, nothing from Sydney or the 645 aboard was recovered.

On 6 February 1942, a Carley Float containing a dead body was spotted just off Christmas Island and towed ashore. Examination of the raft and its occupant led the island's inhabitants to believe that they were from Sydney.  Although a 1949 investigation conducted by the Royal Navy stated the raft was not from HMAS Sydney, and while some historians agreed, others concluded that the raft and the body originated from Sydney. The body was exhumed in October 2006 and reburied at Geraldton Cemetery in November 2008, after DNA was extracted. Attempts to compare the DNA with relatives of Sydney personnel have not been able to identify the unknown sailor.