RMS (Royal Mail Ship) Leinster was a vessel operated by the City of Dublin Steam Packet Company, served as the Kingstown (now Dún Laoghaire)-Holyhead mailboat until she was torpedoed and sunk by German submarine UB-123 on 10 October 1918, while bound for Holyhead. She went down just outside Dublin Bay at a point 4 nautical miles (7.4 km) east of the Kish light. Over 500 people perished in the sinking – the greatest single loss of life in the Irish Sea.
The official death toll was 501, out of a total of 771 (77 crew and 694 passengers), which translates to roughly 65% of the souls on board. 2018 Marks the 100 year aniversary of the sinking of the shop on October 8th 1918. World war I was to end just over a month later on November 11th. See a model of the Wreck of the Leinster on Sketchfab