Even before Leo became "King of the World," the sinking of the Titanic was one of the most captivating moments in U.S. history.

Even before Leo became "King of the World," the sinking of the Titanic was one of the most captivating moments in U.S. history. COSI surely knows our obsession with the big boat, because tonight's pre-party marks the return of "Titanic: The Artifact Exhibition," the museum's most visited centerpiece. Get a chance before the public opening on Saturday to experience the re-creations of first- and third-class quarters, a 3,000-pound section of the hull, 100 new artifacts and much more. The Steerage Party will feature an Irish band, dance floor, cash bar and tasty hor d'oeuvres. Can't make tonight? The exhibit runs though Sept. 6.