Sao Paulo, Brazil (Web Desk): A 22-story abandoned office building occupied by hundreds of squatters was engulfed in flames and collapsed in the centre of Sao Paulo early Tuesday, shooting a massive black cloud of smoke into the sky and red-hot chunks of debris into nearby structures, international media reported.

According to details, at least one person died and three others were missing, a fire department spokesman said. According to authorities, 400 people were registered as living in the building, which belonged to the government.

The cause of the fire was not known.

Live television images in the early morning hours showed a firefighter on an adjacent rooftop talking to a man clinging to a rescue rope and trying to escape from the upper part of the burning building.

Suddenly, the structure collapsed and the man disappeared into the rubble. Authorities said he likely died but were searching for him. In the afternoon, firefighters continued searching for additional victims amid concrete chunks and twisted metal pipes.

An adjacent building caught fire but was evacuated and no one was injured. That blaze was brought under control relatively quickly.

The abandoned former office building had 22 stories, according to the fire department and not 26 stories as reported by some media. It once housed a branch of Brazil’s federal police and had been occupied by squatters for the past seven years.