On 30 December 1915, Natal was lying in the Cromarty Firth with her squadron, under the command of Captain Eric Back. The captain was hosting a film party aboard and had invited the wives and children of his officers, one civilian friend and his family, and nurses from the nearby hospital ship Drina to attend. A total of seven women, one civilian male, and three children were in attendance that afternoon.
Shortly after 15:25, and without warning, a series of violent explosions tore through the rear part of the ship. She capsized five minutes later.
Some thought that she had been torpedoed by a German U-boat or detonated a submarine-laid mine, but examination of the wreckage revealed that the explosions were internal. The divers sent to investigate the ship reported that the explosions began in either the rear 9.2-inch shellroom or the 3-pounder and small arms magazine.
The Admiralty court-martial into the causes of her loss concluded that it was caused by an internal ammunition explosion, possibly due to faulty cordite.
The Admiralty issued a revised list of the dead and missing that totaled 390 in January 1916, but did not list the women and children on board that day.
Losses are listed from 390 to 421.
With her hull still visible at low water, it was Royal Navy practice on entering and leaving Cromarty right up to World War II for every warship to sound "Still", and for officers and men to come to attention as they passed the wreck. After numerous attempts, much of the ship was salvaged. The remainder was blown up in the 1970s to level the wreck so that it would not be a hazard to navigation.