The heaviest rains in decades caused floods and landslides that killed at least 89 people in Rio de Janeiro state, shutting down transport and commerce today in Brazil's second city.
Mudslides swept away shacks in Rio's hillside slums, turning the city's main lake and the sea brown during the round-the-clock heavy rains.
Morning flights in and out of the city of six million people - which will host the 2014 soccer World Cup and the 2016 Olympics - were cancelled or seriously delayed and many neighbourhoods were cut off from power and transport.
Most victims died in more than 180 mudslides, authorities said. A spokesman for Rio's fire service said at least 40 injured people were taken to hospitals as the search went on for others reported missing.
"The situation is critical. Roads are flooded and blocked," Mayor Eduardo Paes told Reuters. "We recommend people stay at home."
Mr Paes told reporters at least 26 people had died in the Rio metropolitan area. The fire service said a total of 89 people were killed across the state.
The mayor said 10,000 houses remained at risk, mostly in the slums where about a fifth of Rio's people live, often in precarious shacks that are highly vulnerable to heavy rains.
Joabes Araujo da Silva, a 21-year-old telemarketer, told Brazil's Globo news he lost everything in the mudslide that swept away his house in the Buraco Quente neighbourhood.
"I only got out of the house, which was full of mud, when my dad pushed the door open. We couldn't get out the window. It was the scariest thing when I saw the house I've lived in for 20 years fall," he told Globo.
The family is now at an uncle's house, wearing borrowed clothes, Globo reported.
The downpour, which began late on Monday, is the worst Rio has recorded in 30 years.
In less than 24 hours, Mr Paes said, 28.8 cm (9 inches) of rain fell on the city - more than what meteorologists said was expected for all of April. After a break, heavy rains began again by mid-afternoon, raising fears of more mudslides.
The latest flooding and transportation chaos will renew attention on Rio's poor infrastructure as it prepares to host the World Cup and the Olympics.
The southern hemisphere summer has been particularly hot and rainy in Rio this year.
In January, at least 76 people died in flooding and mudslides in Brazil's most-populous states of Rio, Sao Paulo and Minas Gerais. Then, dozens of people were killed in a landslide at a beach resort between Rio and the port city of Santos.
President Luiz Inacio Lula da Silva cancelled an event today where he was due to inaugurate public works projects.
"No one could cope with the rain that we are seeing, which is the worst in Rio's history," Mr Lula said.
Globo showed images of houses that slid down a ravine, crumbling to pieces under the mud. Rescuers pulled people to safety from cars stranded in waist-high rushing water.
At least three residents of a slum in Rio's northern zone, including a five-month-old baby, were killed when a mudslide hit two houses, according to media reports.
"When I opened the door, the water came rushing in just like a waterfall," said Jessica Tavares, a 24-year-old student.
The water flooded the apartment and left plants, trash and even fish on her floor, she said.
Television images showed central parts of Rio flooded and abandoned cars under water. Near Copacabana beach, residents waded through ankle-deep water on their way to work but many commuters got stuck in traffic and returned home.
Reuters