Torrential rains over a five-day period spawned Christmas Eve mudslides in Petropolis, a popular weekend retreat for residents of Rio de Janeiro, in what officials called the worst natural disaster in the state in recent years. At least 50 people were killed when their homes were buried on slopes denuded of trees and other plants that would normally hold the soil. The city of Rio de Janeiro suffered no damage, but Petropolis may take weeks to recover.