The Royal Oak battleship
The Royal Oak battleship was completed in 1916. The ship was not considered worth modernizing and would have been withdrawn from service but for the outbreak of the Second World War.
On 14th October 1939 the Royal Oak was torpedoed by the U-47 captained by Gunther Prien inside Scapa Flow. The ship exploded with the loss of 833 lives.
Primary Sources
(1) Primo Levi, Survival in Auschwitz (1947)
Last spring the Germans had constructed huge tents in an open space in the Lager. For the whole of the good season each of them had catered for over 1,000 men: now the tents had been taken down, and an excess 2,000 guests crowded our huts. We old prisoners knew that the Germans did not like these irregularities and that something would soon happen to reduce our number.