SAO PAULO (AP) – Raging torrents from a ruptured dam swamped a rural town in Brazil, killing a young girl and destroying at least 500 homes in a region already devastated by weeks of floods, authorities said Thursday.

Amateur video footage showed water inundating the northeastern village of Cocal, home to about 25,000 people, after the dam failed Wednesday night.

“It was like a tsunami,” Piaui state Gov. Wellington Dias said after visiting the area.

“What I saw was frightening. It was a wall of water 20 meters high, equivalent to a three-story building,” Dias was quoted as saying on a Web site operated by SBT television.

Four people were still missing, Dias added. He said authorities began evacuating some families from their homes about two hours before the dam failed.

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 54 people have been killed and more than 415,000 displaced.

Heavy rains in recent days swelled the reservoir behind the dam, increasing pressure that opened a 165-foot tear and eventually led to the rupture, the Piaui state government said in a statement.

A 12-year-old girl who lived near the dam was killed when the torrents reached her house, authorities said.