The Miami-Dade Fire Rescue received a call at around 1:30 a.m. local time about a partial collapse at the Champlain Towers South condominium in the small, beachside town of Surfside, about 6 miles north of Miami Beach. A massive search and rescue operation was launched before dawn, as crews carefully checked the wreckage and remaining structure for survivors. So far, rescuers have pulled 35 people who were trapped inside the building, two of whom were beneath rubble, according to Miami-Dade Fire Rescue Assistant Chief Ray Jadallah.
Footage from the scene showed firefighters pulling a boy from the rubble alive and rescuing other people from still-standing balconies.
Jadallah told reporters that at least 10 people were assessed and treated on site, while two were transported to local hospitals. One of them has since died.
Aventura Hospital and Medical Center, about 8 miles northwest of Surfside, has received three patients from the scene so far. Two have critical injuries while the third is in fair condition, a hospital spokesperson told ABC News.
The oceanfront condominium has 136 units, and approximately 55 of them collapsed on the northeast corridor, according to Jadallah. The Miami-Dade Fire Rescue has sent more than 80 units to the scene and is leading the search and rescue efforts, which Jadallah said are still ongoing. It was unclear how many residents were unaccounted for.
Multiple police and fire departments from across Miami-Dade County have been deployed to the scene to assist.
Witnesses told Miami ABC affiliate WPLG that more people are still trapped inside the building.
Surfside Mayor Charles Burkett told reporters that the condominium was built in the 1980s and was believed to be substantially full at the time of the collapse. The building was undergoing roof work, he said.
Some 15 families walked out of the building alive 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 but there were no signs of survivors at that time, the mayor said.
Miami-Dade County Mayor Daniella Levine Cava called the incident “unimaginable” and thanked the “brave” rescuers.
“We need to allow them to do their work because every minute in this search can make a huge difference,” Levine Cava said during a press conference in Surfside on Thursday morning.
Florida Gov. Ron DeSantis told reporters that he has spoken to local officials regarding the building collapse and plans to travel to the scene soon.
“It’s a really, really tragic situation, so we’ll hope for the best in terms of additional recoveries,” DeSantis said during a press conference in Tampa on Thursday morning. “But we are bracing for some bad news, just given the destruction we are seeing.”
One 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 were both rescued.
People in neighboring buildings have been evacuated to a local recreational center, another witness told ABC News.
The cause of the collapse was unknown. The Miami-Dade Police Department is investigating the incident. Freddy Ramirez, director of the Miami-Dade Police Department, told reporters that investigators will conduct a “thorough” probe and hope to provide “closure” to the affected families.
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’ Kendall Coughlin, Victor Oquendo and Rachel Katz contributed to this report.