It could take months to know the cause of the South Florida condo collapse that so far has killed at least four people

Three of the four victims have been identified, according to Dr. Emma Lew, director of the Miami-Dade County Medical Examiner Department. One victim died at a hospital. No other information was provided Friday.

About 55 of the 136 units at the building a few miles north of Miami Beach collapsed at around 1:30 a.m. Thursday, leaving huge piles of rubble on the ground and materials dangling from what remained of the structure, officials said.

Thirty-five people were rescued from standing portions of the building by first responders, Jadallah said Thursday.

The number of people unaccounted for rose to at least 159 from 99, Cava said Friday. She added the figure refers to those who may have been within the complex.

“So those are people that maybe live there, but we don’t know whether they were there at the time,” Cava said.

Officials do not know how many people were in the building at the time of the collapse, Surfside Town Manager Andy Hyatt said.

“I had actually called them to tell them I had just booked a flight to come visit because they’ve been asking me to come see their home and to meet their daughter I haven’t met her due to the pandemic,” Sarina Patel said.

They were home at the time the collapse took place, Sarina Patel told Cuomo.

“We have tried calling them countless of times and there’s just been no answers, text messages, nothing,” she said. “They haven’t contacted anybody.”

Mystery over the cause of the collapse

The cause of the collapse remains unknown, and an expert told CNN that the conclusion could take months.

Kobi Karp, an architect and Miami resident, said forensic engineering will be required to determine the cause.

“This is an event that we have never had before. You can look at it; you can speculate how it happened. But at the end of the day, it will take us months to figure out,” he explained.

He added that a portion of the building collapsing while the other stood is a “mystery.”

“At the end of the day for this to crash like this is a very unique and special situation,” Karp said.

Structural engineer Kit Miyamoto also spoke to CNN on Friday night about possible causes, including that it could be corrosion of the metal inside the column, or settlement or sinking of one area of ground at a different rate than others, or a combination of different factors.

“The question is why the column failed?” he said. “A building is actually hard to collapse. There’s a lot of redundancies in the building system. That’s why you don’t see collapses like this.”

Miyamoto pointed out that even in places like California where big earthquakes are common, collapses such as this are extremely rare.

Search efforts continued throughout the night, with crews from Miami-Dade Fire and Rescue working alongside three other state task forces, Miami-Dade Fire Chief Alan Comisky said. International crews from Mexico and Israel arrived on the scene to help on Friday.

The Federal Emergency Management Agency said it sent three Urban Search and Rescue teams to assist with the search.

Additionally, structural engineers have been shoring up other places — such as areas near a parking garage underneath the rubble — to allow crews to tunnel underneath with light machinery.

“We have the best people for the job, and we have the right people for the job. The people who are here are highly skilled and trained,” Cava said. “They continue to believe that there are people that they can reach.”

Building officials: There were no known structural issues

With the cause of the collapse seemingly out of reach in the immediate days, officials familiar with the building have repeatedly said they were not aware of problems that could lead to its collapse.

Donna DiMaggio Berger, an attorney for the Champlain Towers condo association, said board members did not know any information that would have foreshadowed Thursday’s disaster.

The building was undergoing a 40-year recertification process, and the board only knew what the engineer’s certification report included in terms of repair work, she said.

“Typical things that an engineer looks for in a certification report in Miami-Dade and Broward County, which are the two counties that require this kind of certification, is a review of the roof, the HVAC system, electrical, plumbing, and the building envelope,” Berger told CNN.

“But certainly, there was nothing hazardous that was outlined in that report, anything that would have proven to be a danger to life.”

She reiterated the building was safe to live in, as far as she and the board members knew.

The complex was constructed in 1981, according to online Miami-Dade property records. Building standards were strengthened after the highly destructive Hurricane Andrew in 1992.

“What that tells you is … nothing like this was foreseeable, at least it wasn’t seen by the engineers who were looking at the building from a structural perspective,” Kenneth Direktor, an attorney for the association of residents at the condo, told CNN previously.

Direktor, an attorney for the association of residents at the condo, said the building had “thorough engineering inspections over the last several months” in preparation for compliance with a 40-year certification.

A class-action lawsuit filed Thursday alleges that the association of the collapsed condo is responsible for “failures to secure and safeguard” the lives and property of condo owners.

Direktor responded on behalf of the association saying, “I don’t know what caused this building to fall down … The engineers don’t know with certainty what caused this building to fall down.”