Well, Baltimore is a good example of how these come out. Inner Harbor, the Ravens Stadium, and Camden Yards, home of the Orioles, and a fairly sizable tourist-trap area. Hard Rock, trendy little shops, restaurants on the water. Whole thing bought and bonded by the Md. taxpayer. Meanwhile, the entire city of Baltimore north and west of the Inner Harbor is rotting. They're out of money. Schools, roads and bridges worn out. A rust-bucket industrial region in need of demolition and cleanup lies waiting, but there's no money to clean it up. But all those jobs they promised if only they would build these stadiums have yet to materialize. Turns out peanut vendors at the stadiums aren't real regular, and there wasn't so much revenue brought in by the fans and players after all.
Washington DC is another, building a billion dollar baseball stadium in a fairly depressed, crime ridden area hoping against hope it will re-vitalize the area. Problem is, not many folks will go there once the novelty wears off. Then they'll be stuck with an expensive monstrosity, too.
Amazing..