Feb 14 08:27 AM US/Eastern LAS VEGAS (AP) - Sin City is honoring one of its earliest relationships with the grand opening of a museum dedicated to the mobsters that made this desert town. The Mob Museum opens in downtown Las Vegas on Tuesday - the 83rd anniversary of the St. Valentine's Day Massacre, the mass killing that saw Al Capone seize control of the Chicago mob. It's the second mob-themed attraction to open in Las Vegas in a year. The Mob Experience at the Tropicana casino quickly shut down because of slow ticket sales and various internal problems. It's slated to reopen soon. City officials say their version will perform better because it's more authentic. The museum is housed in a former federal courthouse where a U.S. Senate hearing on organized crime was held in the early 1950's.