The largest single loss of life commemorated on the memorial is from the sinking of the RMS '' Lusitania '' on 7 May 1915 . Of the 1,200 dead , over 350 British crew members are commemorated on the Mercantile Marine memorial . In total , the First World War memorial records the names of some 12,000 casualties
the sinking
Sinking of the RMS Lusitania
Tower Hill Memorial