Complex sentence: Her keel was laid down on 1 July 1944 at the New York Naval Shipyard of New York, New York; however, on 12 August 1945, when "Reprisal" was about half complete, construction was cancelled due to an accident.
Split into simpler sentences: Her keel was laid down on 1 July 1944, at the New York Naval Shipyard, of New York, New York. On 12 August 1945, when "Reprisal" was about half complete, construction was cancelled due to an accident.