Original Documents from the National Archives, Kew:
The sinking of the LUSITANIA, 1915
The British passenger ship LUSITANIA, 30,396 BRT, was sunk by the German submarine
U-20 on 7th May 1915 south of Ireland - torpedoed without warning. 1,201 men, women
and children were killed.
ADM 137/4152 - U-boat history sheets comp. By Lt.Cdr. Tiarks :
U-20 sunk the LUSITANIA on May 7, 1915. Sheet No. 4 shows the exact position
of U-20 off the Irish South Coast, while the LUSITANIA is arriving from the West.
Every 4 hours U-20 gave its position by W/T - deciphered immediately by the British Admiralty, Room 40.
Operations Known to British Intelligence: U-20, 1914-1916, 17 pages
ADM 137/4353 - Lusitania signals and copies :
W/T messages, 6 pages
ADM 137/3923 - Photographic plates of log book of U-20 for May, including record of sinking of the LUSITANIA :
War diary U-20, May 1915, 7 pages