USS Arlington (LPD 24), a San Antonio-class amphibious transport dock, is the third ship of the United States Navy to be named for Arlington, Virginia, the location of the Pentagon. Like its sister ships, USS New York and Somerset, the ship is named in commemoration of the Sept. 11, 2001 attacks. Steel recovered from the Pentagon after the September 11 attacks is displayed aboard in the ship's museum. Arlington's keel was laid down on May 26, 2008, at Northrop Grumman's Ingalls shipyard in Pascagoula, Mississippi. Builder's Trials of the ship started on Aug. 21, 2012 and were completed on Aug. 30, 2012. The ship completed Navy Acceptance Sea Trials on Nov. 2, 2012. The U.S. Navy formally accepted the ship on Dec. 7, 2012 and the crew moved aboard. Arlington arrived at its homeport in Naval Station Norfolk, Virginia on March 22, 2013 in preparation for commissioning. Officially, the ship was commissioned on Feb. 8, 2013, but its ceremonial commissioning occurred on April 6, 2013 at Naval Station Norfolk.