25 January 1917: The loss of HMS Laurentic OTD with 3200 gold bars onboard. She was an armed merchant cruiser converted from a passenger liner and was sunk off the mouth of Lough Swilly, Co Donegal after striking German mines. With 3,211 gold ingots each weighing 40lb worth a total of £5 million (net worth in 1917) aboard and intended to pay for war supplies, under the command of Captain Norton, Laurentic left Liverpool, United Kingdom bound for Halifax, Canada on 23rd January 1917. 

Around 5.55pm, 3 miles outside the mouth of Lough Swilly , off Malin Head, the Laurentic suddenly hit a German mine, striking her forward end of the port side, followed by hitting a second mine, striking the area of her engine room on the port side. With Laurentic sinking the survivors started to evacuate the ship in the lifeboats; as the power had failed, there was no light aboard the sinking ship. Laurentic sank within about an hour. The last person to leave the ship was the Captain. Those in the lifeboats were not safe – it was a terrible freezing cold winter’s night. The rescue was slow with some being rescued in the morning; others as late as the afternoon. Of the 475 people aboard Laurentic only 121 survived the tragedy resulting from an act of war.

About 45 minutes after the explosion Captain Norton, using an electric torch, searched the ship for survivors. He then boarded a lifeboat, and was the last to leave his ship.  He stated:

To the best of my knowledge, all the men got safely into the boats. The best of order prevailed after the explosion. The officers and men lived up to the best traditions of the navy...The deaths were all due to exposure, owing to the coldness of the night. My own boat was almost full of water when we were picked up by a trawler the next morning, but all the men in the boat survived. Another boat, picked up at 3 o'clock in the afternoon, contained five survivors and fifteen frozen bodies. They had been exposed to the bitter cold for over twenty hours.

Another boat, found 20 hours after the sinking, contained 17 men dead from hypothermia.[In total 354 men were killed and 121 survived: 12 officers and 109 ratings.] The survivors were given a civic reception in the Guildhall, Derry, where each man was given a ten-shilling note and a packet of cigarettes.

https://en.wikipedia.org/wiki/SS_Laurentic_(1908)

The following day, the Swilly Hotel where officers had dined the night before, was converted into a makeshift morgue for the casualties. Of the 470 crew aboard the ship, 354 lost their lives at sea. Many bodies were washed up for weeks afterwards. Some victims of the tragedy are buried at St Mura's Church in Fahan, as well as Cockhill graveyard in Buncrana.

https://www.govisitinishowen.com/wp-content/uploads/2020/01/THE-SINKING-OF-THE-SS-LAURENTIC.pdf

Most of the gold aboard was recovered by the Royal Navy between 1917 and 1924, during over 5,000 dives to the wreck. The last gold to be found at the wreck site was in the 1930’s. Despite some unsuccessful efforts since to recover more, it is believed that 22 bars of gold are still hidden somewhere at the wreck site of Laurentic today.

71 of dead were buried in one large grave in Fahan churchyard with an ecumenical service. The Admiralty afterwards erected a monument over the grave inscribed with the names of the officers and men interred there. Others are buried in the many graveyards around Lough Swilly and beyond.

https://www.donegalcoco.ie/yourcouncil/communicationsoffice/pressreleases/remembering%20the%20laurentic%20tragedy%20100%20years%20on/

https://en.wikipedia.org/wiki/SS_Laurentic_(1908)