RIO DE JANEIRO, Brazil — Flash floods caused by torrential rain killed at least three people in Rio de Janeiro, officials said on Tuesday, as emergency workers raced to rescue people trapped in buses, cars and buildings.

Heavy rain overnight inundated parts of the city, turning some streets into raging rivers, toppling trees and sweeping away cars as the state emergency agency declared a crisis.

The southern zone of the city, which includes Copacabana, Ipanema and Leblon as well as several favelas, was the hardest hit.

A man was killed after he was caught in flooding, while two women died when a house in a favela collapsed, Rio de Janeiro mayor Marcelo Crivella said.

At least one person is missing, G1 reported. Cars and buses were crushed by fallen trees.

Many people returning home in the southern suburbs on Tuesday evening were drenched as they waded through knee-deep water in the relentless downpour.

“Many houses in Rio are built in areas that are inappropriate, in places where water flows. It’s a tragedy and we have tried to warn these people,” Crivella said.

Schools throughout the city suspended classes and power was knocked out in some areas as heavy rain continued to fall on Tuesday, complicating rescue and cleanup efforts.

Some people walking to work were forced to climb fences to avoid flooded streets as they tried to reach their offices.

Crivella told Globo TV that the downpour had been “atypical.”

Heavy rain often causes flash flooding in Rio de Janeiro as the volume of water overwhelms the city’s creaky infrastructure and brings traffic to a halt.

Impoverished favelas spread across hills throughout the city are usually the hardest hit.

Torrential rain in February killed at least six people in Rio de Janeiro. — AFP