At least three people are dead and 99 others are unaccounted for after a 12-story residential building partially collapsed in southern Florida's Miami-Dade County early Thursday, officials said.
The partial collapse of the Champlain Towers South condominium in the small, beachside town of Surfside, about 6 miles north of Miami Beach, was reported around 1:30 a.m. local time. The oceanfront complex has 136 units, and approximately 55 of them collapsed along the northeast corridor, according to Miami-Dade Fire Rescue Assistant Chief Raide Jadallah.
A massive search and rescue operation was launched before dawn and crews are still carefully combing through the wreckage and remaining structure in hopes of finding survivors. So far, crews have rescued 35 people who were trapped in the building and two others from beneath the rubble, Jadallah told reporters.
A Miami-Dade County official confirmed to ABC News that the death toll was up to three.
Teams of firefighters have been cutting through the rubble and placing sonar devices as part of the search efforts, which continued overnight. Responders have not heard any voices coming from the pile but have picked up "a possibility of a banging," according to Jadallah.
"This process is slow and methodical," Jadallah said during press conference in Surfside on Thursday afternoon. "Every time there's a shift in the rubble, we have additional rubble that shifts on us."
Miami-Dade County Mayor Daniella Levine Cava told reporters that 102 people have now been accounted for but at leat 99 others remain missing. She said search and rescue crews will be "working around the clock."
"As the day comes to an end, their day does not," Levine Cava said during a press conference in Surfside on Thursday evening.
"We need to allow them to do their work because every minute in this search can make a huge difference," she said at an earlier press conference.
Jadallah told reporters that at least 11 people were medically assessed and treated on site, four of whom were then transported to local hospitals.
Aventura Hospital and Medical Center said it has received three patients from the scene -- two in critical condition and one in fair condition -- while Jackson Health System said it received two patients.
A "substantial number" of the condominium's residents are foreigners, according to Florida Sen. Marco Rubio.
Paraguay's foreign ministry said that six Paraguayan nationals were in the building and are still missing: Sophia López-Moreira, the sister of the country's first lady; her husband, Luis Pettengill; their three children; and their nanny, Lady Luna Villalba. Paraguayan President Mario Abdo Benítez canceled his events due to the incident.
Meanwhile, Argentina's consulate in Miami said that nine Argentine nationals are missing. Venezuela's ambassador to the United States confirmed that four Venezuelan nationals are missing. Uruguay's foreign ministry said that three Uruguayan nationals have been affected by the incident, though their status was unclear. Colombia's foreign ministry also reported that six Colombian nationals resided in the condominium and officials were still trying to determine whether they were there at the time of the collapse.
Florida resident Soriya Cohen told ABC News that her husband, Brad Cohen, a 51-year-old orthopedic surgeon, and her brother-in-law, Gary Cohen, a doctor visiting from Alabama, both are missing. Soriya Cohen said they haven't been answering their phones and she does not have hope that they are alive.
"Just look at that rubble," Soriya Cohen told ABC News, pointing at the wreckage.
She said she and her daughter were staying in a different home at the time because their family is in the process of moving. Her son is currently studying abroad and trying to get home, she said.
“It’s been surreal,” she added. “My daughter has been in absolute shock.”
Gabe Nir, who lives in the Champlain Towers South with his mother and sister, told ABC News that they ran from the building when they heard the collapse.
Nir said he felt a second, more intense collapse and that they ran for their lives as a thick cloud of white dust enveloped them, making it hard to breathe. Nir, who compared the collapse to an earthquake, said he's grateful to be alive.
Another witness told ABC News that his wife cares for an elderly woman who lives in the condominium and frantically called him around 1:15 a.m. local time, after the units next door came crashing down. He said his wife and the elderly woman both were rescued.
A Miami-Dade county official told ABC News it's been difficult to determine how many people were in the collapsed section of the building, partly due to the fact that there isn't an on-scene management company that keeps track. The condominium is a mix of full-time residents, seasonal residents, renters and short-term visitors, so authorities have been relying largely on neighbors and word of mouth.
Miami-Dade County has an urban search and rescue team that has been dispatched to earthquakes and other disasters all around the world, but this is the first time that the team has been deployed on home turf, according to the official.
The official told ABC News that there's real concern about the structural integrity of the remaining building, particularly from dangling wires and portions of concrete. Fires have flared up throughout the day, adding to the danger for the search and rescue teams, the official said.
The unaffected section of the condominium was cleared as of 8 a.m. local time. But due to the lingering dangers, several blocks of the complex will be closed for the next week, according to the official.
Surfside Mayor Charles Burkett called the partial collapse a "catastrophe." He told reporters that the condominium was built in the 1980s and was believed to be substantially full at the time of the partial collapse. The building was undergoing roof work, he said.
Some 15 families escaped the building on their own and were put up in a local hotel, according to Burkett. Search dogs did an initial pass around the wreckage when it was still dark and the site was considered dangerous, but there were no signs of survivors at that time, the mayor said.
Surfside Commissioner Nelly Velasquez told ABC News that the building was up for its 40-year recertification.
The Champlain Towers South Condo Association was preparing to start a new construction project to make updates and the condominium had been through extensive inspections, according to Kenneth Direktor, a lawyer for the association. Direktor said that he hadn't been warned of any structural issues with the building or about the land it was built on. He said there was water damage to the complex, but that is common for oceanfront properties and wouldn't have caused the collapse.
"Nothing like this has ever been seen, at least not in the 40 years I've been doing this," Direktor told ABC News.
Florida Gov. Ron DeSantis toured the site, telling reporters it was "traumatic to see."
"It's a tragic day," DeSantis said during a press conference in Surfside on Thursday afternoon. "We still have hope to be able to identify additional survivors."
The governor declared a state of emergency in Miami-Dade County that evening "to provide assistance for the families impacted by the Surfside tragedy," according to the order.
U.S. President Joe Biden told reporters that he spoke with the Miami-Dade County mayor as well as U.S. Rep. Debbie Wasserman Schultz, who represents the Florida district.
Biden said he was waiting on the governor to ask for an emergency declaration, but he is "ready to move from the federal resources immediately, immediately, if in fact we're asked for it."
The cause of the collapse was unknown. The Miami-Dade Police Department is leading an investigation into the incident.
"Our goal is to provide a thorough investigation and closure for our families," Freddy Ramirez, director of the Miami-Dade Police Department, said during a press conference in Surfside on Thursday morning.
Authorities have opened a family assistance center at the Surfside recreational center for individuals unable to locate loved ones who live in the Champlain Towers South. Anyone with family members from the condominium who are either safe or still missing is urged to call 305-614-1819 to account for them.
ABC News' Eliana Larramendia Boyd, Kendall Coughlin, Christopher Godburn, Aaron Katersky, Rachel Katz, Victor Oquendo, Ben Stein, Christine Theodorou and Nery Ynclan contributed to this report.