“Everyone who is alive is out of the building.” That's what the head of Miami-Dade Emergency Management told reporters after this tragic event.

A wing of the 12-story building in the community of Surfside came down with a roar around 1:30 a.m. By late afternoon, nearly 100 people were still unaccounted for, authorities said, raising fears that the death toll could climb sharply. Officials did not know how many were in the tower when it fell.

Teams of 10 to 12 rescuers at a time entered the rubble with dogs and other equipment, working until they grew tired from the heavy lifting, then making way for a new team, said Florida Chief Financial Officer Jimmy Patronis, the state’s fire marshal.

Authorities did not say what may have caused the collapse. On video footage captured from nearby, the center of the building appeared to fall first, with a section nearest the ocean teetering and coming down seconds later as a huge dust cloud swallowed the neighborhood.

The Associated Press contributed to this story. 

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