Heavy Rains have caused a dam to rupture in northeastern Brazil, stranding almost 3,000 people in a region where floods have killed 53 people and displaced more than 415,000, authorities said Thursday. Officials said they launched an overnight rescue operation using five helicopters to assist almost 600 families stranded by Wednesday's dam rupture in Piaui state. Piaui civil defense department spokeswoman Vanize Lemos said that 150 families have been rescued. She said some residents climbed trees and rooftops after a river rose 5 meters. Heavy rains have devastated northern and northeastern Brazil since April, causing floods and mudslides in a huge region extending from the Amazon rain forest to the Atlantic Ocean.