 After her May 1915 commissioning , O 'Brien sailed off the east coast and in the Caribbean . She was one of seventeen destroyers sent out to rescue survivors from five victims of German submarine U @-@ 53 off the Lightship Nantucket in October 1916 . After the United States entered World War I in April 1917 , O 'Brien was sent overseas to patrol the Irish Sea out of Queenstown , Ireland . 
