This particular piece is a 13-by-30-foot chunk of the hull of the storied British luxury liner that sank in the freezing North Atlantic on April 15, 1912, after hitting an iceberg. More than 1,500 people perished. Salvaged in 1998 from the wreck site 2 1/2 miles below the ocean surface, the bent hull piece, last seen in Las Vegas, is the centerpiece of "Titanic: The Artifact Exhibition,'' opening June 10 on the fourth floor of the Metreon entertainment center.