The mayor of New Orleans late Thursday declared a state of emergency for the city ahead of Tropical Storm Nate, which has already been blamed for 22 deaths in Nicaragua and Costa Rica. The city’s mayor Mitch Landrieu said residents who live outside the city’s levee system or in low-lying areas should move to higher ground. “There is no need to panic,” he tweeted. “Be ready and prepare. Get a plan. Prepare to protect your personal property.” Evacuations were ordered Thursday for parts of Louisiana, including St. Bernard Parish east of New Orleans.