<p>AVONDALE, La. (AP) - A ceremony steeped in shipbuilding tradition kicked off major construction Friday on a U.S. Navy assault vessel named in honor of United Airlines Flight 93, which crashed during the Sept. 11, 2001, terrorist attacks.</p>
<p>It is the second of three new Navy ships named for the sites of the Sept. 11 attacks. The USS New York entered service last month and the Arlington, memorializing the strike on the Pentagon, is under construction.</p>