Ships sunk by military action in the First World War

  "U-boat sinking a troopship" by Willy Stöwer

     http://en.wikipedia.org/wiki/Naval_warfare_of_World_War_I
   http://en.wikipedia.org/wiki/Willy_Stöwer

Full lists, see:

http://www.uboat.net/wwi/ships_hit/largest.html

http://en.wikipedia.org/wiki/Armed_merchantman

http://ahoy.tk-jk.net/MaraudersWW1/Tables.html

Keeling, p. 261 (Voyage database).

Specific examples:

Ancona

Carpathia

Ivernia

Kaiser Wilhelm der Grosse

Lusitania