 The Yugoslav monitor Sava was a Temes @-@ class river monitor built for the Austro @-@ Hungarian Navy as SMS Bodrog . She fired the first shots of World War I on the night of 28 July 1914 , when she and two other monitors shelled Serbian defences near Belgrade . She was part of the Danube Flotilla , and fought the Serbian and Romanian armies from Belgrade to the mouth of the Danube . In the closing stages of the war , she was the last monitor to withdraw towards Budapest , but was captured by the Serbs when she grounded on a sandbank downstream from Belgrade . After the war , she was transferred to the newly created Kingdom of Serbs , Croats and Slovenes ( later Yugoslavia ) , and renamed Sava . 
