Fla. Urges New Evacuations As Ivan Nears MIAMI - Tourists and residents were told Thursday they will have to leave the Florida Keys to avoid mighty Hurricane Ivan, even as the state still struggled with the misery left by Hurricanes Frances and Charley.    Forecasters said Ivan - which strengthened early Thursday to 160 mph - could reach the island chain as soon as Sunday, making it the third hurricane to hit Florida in a month...