Brazil: 37 dead and dozens missing in the worst floods in 80 years | Brazil

Heavy rains in Brazil’s southern state of Rio Grande do Sul have killed 37 people and 74 others remain missing, while unprecedented floods devastated cities and forced thousands of people to flee their homes.

It was the fourth such environmental disaster in a year, following floods in July, September and November that killed 75 people in total.

Flooding across the state has exceeded that seen during a historic deluge in 1941, according to the Brazilian Geological Survey. In some cities, water levels were at their highest since records began nearly 150 years ago, the agency said.

On Thursday, a dam at a hydroelectric plant between the cities of Bento Gonçalves and Cotipora partially collapsed and entire cities in the Taquari River valley, such as Lajeado and Estrela, were completely flooded by water. In the city of Feliz, 80 kilometers (50 miles) from the state capital, Porto Alegre, a massively swollen river washed away a bridge connecting it to the neighboring city of Linha Nova.

Operators reported power, communications and water outages across the state. According to the civil defense agency, more than 23,000 people had to leave their homes.

Without internet, phone service or electricity, residents struggled to provide updates or information to family members living in other states. Helicopters continually flew over cities as families with stranded children waited to be rescued on rooftops.

The downpour began on Monday and is expected to last at least until Saturday, Marcelo Seluchi, chief meteorologist at the National Center for Surveillance and Warning of Natural Disasters, told Brazil’s public television network on Friday.

On Thursday night, Governor Eduardo Leite alerted the state’s population, known as gauchos, about the persistence of rains and floods. The situation is expected to worsen in Porto Alegre, he said.

A family rescued by military firefighters in Lajeado, Rio Grande do Sul. Photograph: Jeff Botega/Reuters

“As a human being, I am devastated inside, like every gaucho,” he said. “But as governor, I stand here firmly and guarantee that we will not falter. “We are doing everything with focus, attention, discipline and indignation, to ensure that everything in our power is done.”

The climate in South America is affected by the El Niño climate phenomenon, a periodic and natural event that warms surface waters in the equatorial Pacific region. In Brazil, El Niño has historically caused droughts in the north and heavy rains in the south.

This year, the impacts of El Niño have been particularly dramatic, with a historic drought in the Amazon. Scientists say extreme weather is occurring more frequently due to human-caused climate change.