by Marc Burleigh with Blanca Morel in Managua Agence France-Presse SAN JOSE, Costa Rica (AFP) — A tropical storm sliding north along Central America Thursday has unleashed heavy rains killing at least nine people in Costa Rica and Nicaragua, with forecasters predicting it could strengthen into a hurricane headed for the United States. Costa Rica declared a national emergency as it struggled with mudslides, washed out roads and overflowing rivers. Schools, universities, government offices and banks across the […]