SAO PAULO (AP) - Raging torrents from a ruptured dam swamped a small rural Brazilian city Thursday, killing four people and destroying at least 120 homes in a region already devastated by more than a month of floods. Eleven people were missing, 80 suffered minor injuries and nearly 3,000 were forced from their homes.
Amateur video footage showed water pouring from the dam into a river below. Officials said floodwaters inundated Cocal, population about 25,000, after a dam section gave way under the weight of a reservoir bloated by rains.
Floods from those rains have killed nearly 60 and left hundreds of thousands homeless in a wide swath of northern Brazil.
"It was like a tsunami," Gov. Wellington Dias of northeastern Piaui state said after touring the devastation zone.
Some residents climbed trees and scrambled atop rooftops after the floodwaters suddenly swelled a river. Globo TV said the rupture sent 50 billion liters (13 billion gallons) of water pouring out of the reservoir, causing flooding that stretched 100 kilometers (62 miles) downriver from Cocal.
"What I saw was frightening. It was a wall of water 20 meters (65 feet) high, equivalent to a three-story building," Dias said, according to a Web site operated by SBT television.
Authorities began evacuating families about two hours after the dam failed, but civil defense authorities said Thursday night that 11 people were still missing and that rescue operations had been suspended until Friday. Churches and other buildings were turned into shelters for the 2,953 people who were displaced.
The dead from the dam rupture included girls ages 10 and 12, a 72-year-old man and a 73-year-old woman, the state government said on its Web site.
Downpours have battered northern and northeastern Brazil since April, causing floods and mudslides in a region extending from the Amazon rain forest to the Atlantic Ocean. Authorities say 59 people have been killed and more than 423,000 were displaced.
Heavy rains in recent days swelled the reservoir behind the dam, increasing pressure that opened a 165-foot (50-meter) tear and eventually led to the rupture, the Piaui state government said in a statement.
"It was a lot of water," resident Antonio Antonino told SBT. "People were desperate, they were crying. I'm 60 years old, and I've never seen anything like this."
The floods also swept away crops and livestock, according to the government statement.
"I heard a very loud thundering noise, and when the dam broke a huge column of water shot up 50 meters (164 feet) into the air, and when it came down it swept away everything in its way," farmer Jose Maria Siqueira told Globo TV.
Officials launched an overnight rescue operation using five helicopters to transport victims to safety, and firefighters were sent to aid the victims.
Piaui Civil Defense spokeswoman Vanize Lemos said at least 150 families were initially rescued.
The heavy rains are blamed on an Atlantic Ocean weather system that normally moves away in April but hasn't budged this year. Meanwhile, southern Brazil has been hit by a drought that has severely affected agriculture.
The flooding in northern Brazil comes just four years after a devastating drought hit the Amazon. Experts fear that the world's largest rain forest may be experiencing severe climate swings brought on by global warming, which could threaten the people and wild animals that live in the region.
Associated Press Writer Alan Clendenning contributed to this report.
Copyright 2013 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.