CHICAGO (CBS Chicago/CBS News) — A University of Chicago student and his girlfriend are among those missing after a deadly condo building collapse in South Florida.

The mother and aunt of the student, Ilan Naibryf, posted to Facebook asking for any information about her son. Also missing is his girlfriend, Deborah Berezdivan.

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Naibryf’s website indicates that he will enter his fourth year in the college at the U of C next year and is studying physics and molecular engineering.

Search and rescue teams were set to work through the night at the site of the building in Surfside, Florida north of Miami Beach.

They used lights, dogs, and every tool they had. First responders said the search and rescue mission will continue around the clock.

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At least 99 people were unaccounted as of Thursday night, though some of them might not have been in the building at the time. Miami-Dade County Mayor Daniella Levine Cava said 102 people have been accounted for so far.

The 12-story building, called Champlain Towers South, collapsed just after 12:30 a.m. Chicago time and took 55 units down with it. It’s not yet clear why the building collapsed — but when the dust settled, the building appeared to be sheared in two, with bunk beds, dining rooms and entire homes left blowing in the wind.

Rescue teams are tunneling below the building in a race against time to find survivors, but officials said it is still too dangerous to send searchers on top of the pile. Hundreds of first responders are on the scene, and President Biden is promising federal aid.

Multiple people were hospitalized, officials said. Ten people were treated at the scene of the huge pile of rubble, according to Ray Jadallah of Miami-Dade Fire & Rescue.

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Florida Gov. Ron DeSantis has declared a state of emergency, opening the door for federal aid.

Surfside Mayor Charles Burkett told CBS Evening News anchor Norah O’Donnell that the collapse was an “unmitigated catastrophe.”

“Buildings like this don’t fall down in America,” Burkett said. “This is this is not an old building. This is a new building. I know old buildings because that was my business,” he said. “This building is 1980s. So it’s like, relatively speaking, brand new. And the extent of the collapse is really mind-boggling.”

Rescuers described the collapse as a pancake collapse, which could make survival possible for some – given that there are voids.

Meanwhile, President Joe Biden pledged aid, families of the missing were being asked for DNA samples, and hundreds of people prayed that survivors would be found.

As CBS 2 Political Investigator Dana Kozlov reported, many who flocked to the beach town’s reunification center shared pictures of their missing relatives and friends.

A nearby surveillance camera captured the collapse, which happened within seconds. Hours later, rescuers pulled a 10-year-old boy from the debris after spotting a hand waving in the rubble.

U.S. Rep. Deborah Wasserman Schultz (D-Florida) said there is a large international and Jewish community in the building, and she is working to secure visas for overseas family members.

First responders said the search is hazardous and painstaking, but they will not stop.

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Reports show the building, built in 1981, had been sinking 2 millimeters a year since the early 1990s. Whether that, roof work, or nearby construction had anything to do with the collapse will be not known at least for days – and more than likely weeks or months.