FLORIDA: Rescue crews near Miami searched through tons of rubble on Thursday for anyone who may have survived the predawn collapse of part of an oceanfront apartment tower, with officials reporting at least one person found dead and nearly 100 more missing.

Search teams detected sounds of banging and other noises but no voices coming from the mounds of debris hours after a large section of the Champlain Towers South condominium in Surfside, a barrier island town across Biscayne Bay from the city of Miami, crumbled to the ground, authorities said.

What caused the 40-year-old high-rise to collapse was not immediately known, though local officials said the tower was undergoing "recertification" repairs and that an adjacent building was under construction.

Miami-Dade Police Director Freddy Ramirez told reporters that 99 people were unaccounted for and that 53 others whose whereabouts were initially unknown had since been located, though he did not make clear whether everyone in the second group was alive.

"Fire and rescue are in there with their search team, with their dogs. It's a very dangerous site right now. Very unstable," Ramirez told reporters. "They're in search-and-rescue mode, and they will be in that mode for a while. They are not quitting. They're going to work through the night. They are not stopping."

Ramirez said the numbers of known casualties and people missing were likely to fluctuate.

"I don't want to set false expectations," he said. "This is a very tragic situation for those families and for the community."

Said Oliver Gilbert, vice chair of the county board of commissioners: "I just have to implore everybody, just pray."

A fire official said 35 people were evacuated from the portion of the high-rise left standing, and two individuals were pulled from the rubble as response teams used trained dogs and drones in the search of survivors. One of those two people was dead.

Sally Heyman, a Miami-Dade County Commissioner, told CNN early in the day that officials knew of 51 individuals who "supposedly" live in the building, home to a mix of year-round residents and part-time "snow birds" who spend the winter months in Florida.

Officials said the building, constructed in 1981, was going through a recertification process requiring repairs.

"There were structural issues obviously - the building did collapse," Miami-Dade Mayor Daniella Levine told reporters. She said structural engineers were working with firefighters to shore up the part of the building left standing.

Jenny Urgelles woke up to the news that her parents' building had collapsed. She called them, but both their phones went straight to voicemail, she told WSVN 7 News.

"I am holding on to hope. I'm very desperate to know what's happening," she told the local Fox affiliate.

Footage from WPLG Local 10, a Miami TV station, showed a rescue team pulling a boy from piles of debris and rebar, and firefighters using ladder trucks to rescue residents trapped on balconies.

The search effort was slowed by at least one fire that burned at the site as emergency crews doused the rubble with water, local media reported.

Authorities were looking for people who might be in the rubble, as well as trying to identify residents who were not home at 1:30 a.m. (0530 GMT), when an entire side of the building gave way.

"We all woke up in the early morning hours to a tragic scene," said Florida Governor Ron DeSantis, who toured the scene on Thursday afternoon. "We still have hope to identify additional survivors."

At least six Paraguayan nationals were among those unaccounted for, Paraguay's Foreign Affairs Ministry said, including the sister of Paraguay's first lady, the sister's husband Luis Pettengill and their three children.

SUBJECT TO VARIOUS INSPECTIONS

The Champlain Towers South had more than 130 units, about 80 of which were occupied. It had been subject to various inspections recently due to the recertification process and the adjacent building construction, Surfside Commissioner Charles Kesl told Local 10.

"There were garage-underground issues related to that, to make sure that it was done soundly," Kesl said. "There were some cracks from that project - minor cracks - that were just patched up. Nothing, based on my understanding, to the magnitude that would indicate that there was a structural problem that could result in something so catastrophic."

Surfside Mayor Charles Burkett said construction work was being done on the roof of the Champlain Towers South but there was no indication that it caused the collapse.

"It's hard to imagine how this could have happened," Burkett told reporters. "Buildings just don't fall down."

Burkett said the collapse left about a third or more of the building - a section with balconies facing the beach - "totally pancaked."

Resident Barry Cohen and his wife were rescued from the building.

"At first it sounded like a flash of lightning or thunder," said Cohen, a former Surfside vice mayor and building resident. "But then it just kept on - steadily for at least 15 to 30 seconds - it just kept on going and going and going."

Cohen also said there had been construction for more than a month on the building's roof.

The Miami-Dade Police assumed control of the investigation. More than 80 fire and rescue units responded, the Miami-Dade County Fire Rescue Department wrote in a Twitter message early on Thursday.