Question: what happened to titanic's sister ship britannic

title: HMHS Britannic
text: Britannic was launched just before the start of the First World War . She was designed to be the safest and most luxurious of the three ships , drawing lessons from the sinking of the Titanic . She was laid up at her builders , Harland and Wolff , in Belfast for many months before being put to use as a hospital ship in 1915 . In 1915 and 1916 she served between the United Kingdom and the Dardanelles . On the morning of 21 November 1916 she was shaken by an explosion caused by a naval mine near the Greek island of Kea and foundered 55 minutes later , killing 30 people . 

Answer: answer: Britannic was launched just before the start of the First World War. She was laid up at her builders for many months before being put to use as a hospital ship in 1915. In 1915 and 1916 she served between the United Kingdom and the Dardanelles. On the morning of 21 November 1916 she was shaken by an explosion caused by a naval mine near the Greek island of Kea and foundered 55 minutes later, killing 30 people.