A 26-story abandoned office building occupied by about 150 squatters was engulfed in flames and collapsed in the center of Sao Paulo early Tuesday, shooting a massive black cloud of smoke into the sky and red-hot chunks of debris into nearby structures, Reuters reported.

At least one person died and three others were missing, authorities said.

The massive fire struck two buildings in Largo do Paissandu on Tuesday, causing one of the properties to suddenly collapse. The neighboring building is still ablaze but fire crews are on the scene.

The fire department has said there is no risk of the second building collapsing, Folha reported.