New Orleans Urges People to Take Shelter NEW ORLEANS - With 135-mph Hurricane Ivan closing in with frightening intensity, this flood-prone city scrambled Wednesday to get people out of harm's way, putting the frail and elderly in the cavernous Louisiana Superdome and urging others to move to higher floors in tall buildings.    Along some 300 miles of threatened coastline from Louisiana to the Florida Panhandle, the churning surf, ominous clouds, swaying traffic lights and escalating winds were all the reminders some people needed to take cover from a storm that made a slight turn north on a path that could bring it ashore early Thursday at the Alabama-Mississippi line, near Mobile, Ala...