A waterfront building collapsed near Miami, killing at least one person and leaving 99 people unaccounted for.

Officials in the southeastern U.S. state of Florida say they do not know the cause of a partial collapse of a 12-story beachfront condominium building early Thursday (June 24). The accident took place in a town north of Miami. The incident left at least one person dead and at least 99 people unaccounted for.

Miami-Dade Fire and Rescue Department Assistant Chief Red Jadala told reporters that first responders were called to the scene in the town of Surfside at about 1:30 a.m. local time. He said the building’s northeast corner collapsed, involving about 55 housing units. Rescuers moved 35 people from the part that didn’t collapse and rescued two people from the collapsed part, he said.

More than 80 emergency rescue units rushed to the scene, he said.

Ten people were treated for injuries at the scene, Jadallah said. Two victims were taken to a local hospital, where one was pronounced dead, said Charles Burkett, mayor of Cereside. Burkett said he was told the collapsed part of the building was filled with occupants and he expected the death toll to rise.

Earlier, Burkett told reporters that it was hard to imagine how the apartment building, built in the 1980s, could have collapsed. “Buildings don’t fall down on their own,” he said.

President Joe Biden said at a press conference Thursday that the Federal Emergency Management Agency (FEMA) was ready to commit and assist in the rescue effort.

He said, “We are prepared to immediately deploy federal resources.”

Florida Governor Ron DeSantis visited the crash site. He said the scene before him was shocking.

“It’s a sad day,” DeSantis said at a press conference Thursday afternoon. “There is still hope that we will be able to find more survivors.”