What We Know About Why the Surfside Condo Collapsed [Updated]

The unfolding tragedy began just before 2 a.m. on Thursday morning, when a wing of a condo building on Collins Avenue in Surfside, just north of Miami Beach, collapsed. 

It’s unclear what caused the Champlain Towers South building to buckle and officials have yet to provide an explanation, but experts and officials have expressed disbelief at the magnitude of the destruction. “It’s hard to imagine how this could happen,” Surfside Mayor Charles Burkett told NBC. “Buildings just don’t fall down.”

As of Sunday afternoon, nine people have been confirmed dead, and 156 residents were still unaccounted for, according to Miami-Dade County Mayor Daniella Levine Cava. In the hours following the collpase, at least 35 people were pulled from the building, while 10 occupants were treated for injuries and two were transported to local hospitals, according to Miami-Dade fire officials.

More fatalities are expected, and the numbers of missing is expected to change as the search and rescue effort continues. It could take days or even weeks to complete. 

While the reason for the collapse remains unclear, a growing consensus seems to point to structural damage near the pool deck area. Engineers had found “major structural errors” in the building in a 2018 report sent to the city of Surfside, the Miami Herald first reported. The report pointed to damage below pool deck area from insufficient waterproofing, and recommended immediate repair.

Industry experts suspect it was due to erosion in the foundation, said Yaniv Levi, owner of Coast to Coast General Contractors, who specializes in concrete restoration of existing buildings. “Over time in South Florida and Miami, with the king tides, the high water levels, erosion took place in the foundation,” Levi said. “Over time it started creating voids, and settlement, and that might have led to the collapse. That’s one of the theories.”

The 40-year recertification

Built in 1981, the Champlain building was undergoing a compulsory inspection required of buildings after 40 years, Surfside Commissioner Eliana Salzhauer told the Miami Herald. The condo association, which is responsible for the upkeep of the property, also took out a $1.3 million loan to refurbish the roof, the commissioner added and property records show. 

Ahead of its inspection, the condo association had solicited bids from contractors in the weeks before the building fell, two general contractors, who were invited to a second round of bidding this coming Tuesday, confirmed. According to a 200-page scope of work document, the building required extensive demolition, repairs, and replacements, costing an estimated $10 million, NBC 6 reported. 

But engineers told the outlet that nothing seemed out of the ordinary and that these types of repairs are common. 

This was not the first time the condo association had solicited bids. Coast to Coast had reviewed an earlier scope of work, back in 2018, in preparation for the approaching 40-year recertification, documents confirm. The repairs were in the range of $2 million in Coast to Coast’s estimation, but no one was ever picked for the job, Levi said. “This building didn’t have a project from what I know in the past 20 years,” he said. “They’ve been just constantly kicking the can down the road.” 

Still, Levi cautioned that such delays still did not explain the collapse. The 2018 scope of work didn’t mention any major defects or refer to any structural integrity issues, he said, and buildings in much worse conditions have not caved in.

A sister building of the collapsed tower, the Champlain Towers East, located a few condos down at 8855 Collins Avenue, has seen more recent upkeep, confirmed Norge Arnaiz, principal of Restore Construction Group, which recently completed work at the property including installing new railings, and some concrete repair. “These buildings require constant maintenance of concrete restoration, painting and waterproofing,” Arnaiz said. 

The 40-year recertification process was put in place after a previous tragedy. In 1974, a depression-era office building in downtown Miami collapsed, killing six. The building was 40 years old at the time, and inspectors found the structure had problems with deteriorating concrete and rusted rebar, explained John Pistorino, a principal at Pistorino & Alam Consulting Engineers. 

In response to the tragedy, Miami-Dade and Broward counties crafted new regulations, requiring inspections for buildings after 40 years, and then every 10 years after that. 

But given the recent tragedy, many are already calling for stricter regulations. “Already, there’s been talk about doing it at 30 years,” Levi said. “I believe they need to do it every 10 years, starting at 20 years.”

Another possibility is putting more focus on the foundation, said Arnaiz. At the moment, the 40-year recertification begins with a visual inspection, and only requires further checks if there are warning signs, and foundations are by definition, not visible. 

But in a climate like South Florida’s, where the ground is limestone bedrock, allowing ocean water to seep through, along with frequent flooding and significant storms, that should be a greater emphasis.

“Basements get flooded with water,” he said. “If they get water in there, and it’s sitting underwater for days, weeks, year after year. When you have these king tides, obviously that’s part of the problem.” 

Climate and subsidence

Others have also drawn attention to the specifics of the region’s climate, including a 2020 report on subsidence that specifically called out this property.

Constructed on reclaimed wetlands, the tower had been sinking at a rate of roughly 1 to 3 millimeters during the 1990s, according to a report by a Florida International University professor. “I looked at it this morning and said ‘Oh my god.’ We did detect that,” Professor Shimon Wdowinski told USA Today, which first reported about the study.

Nevertheless, Wdowinski repeatedly cautioned that the movement, known as subsidence, was unlikely to be responsible for the collapse. 

The study used a technology called InSAR to track land subsidence in Norfolk, Virginia and Miami Beach between 1993 and 1999. 

“It’s pretty common in Florida that this technology can detect movement of buildings, and in most cases these buildings just move, there’s no catastrophic collapse like in the case here in Surfside,” he said in an interview for FIUNews Thursday.

“The building can move due to the land, or it can be due to cracks within the building, and there are hundreds of buildings who have cracks and they move (not necessarily in Miami)… and it doesn’t mean it will collapse,” Wdowinski continued. “What happens here is there was something from the engineering point of view that caused it to collapse.”

The reason they had reported this property, he said, was because it was in an area where they weren’t expecting it, and nearby buildings weren’t showing similar movement.

Even with these warning signs, experts are bewildered about how a building, simply, collapsed.

“This was an unpredictable catastrophe,” said Adam Mopsick, CEO of Amicon, a Miami-based construction management firm, which has constructed several seaside condos. 

Neither Mopsick and Pistorino offered any theories about the failure of the Surfside building and said it was impossible to know without a thorough examination of the accident site.

Condo attorney Ryan Poliakoff conceded that oceanfront buildings are under great stress from the wind and salt and regularly need a fresh coat of paint. “But even with that, I’ve never heard anyone say, ‘If you don’t maintain it, after 40 years, the building is going to fall down,’” the lawyer added. 

Given their wealth, Surfside and Champlain were unlikely candidates for such a tragedy. Situated just north of Miami Beach, Surfside is an upscale beach community, where ocean-front apartments commonly sell for millions. 

In 2011, a 1,683-square-foot unit at Champlain sold for $500,000, according to property records. Only a block away, former White House advisors Ivanka Trump and Jared Kushner this year had rented an apartment at the luxurious Arte condo building.

The tragedy may even turn into an international affair. The sister-in-law of the President of Paraguay, Sophia López Moreira, and her family are said to be missing. “I’m not losing hope,” Moreira’s aunt said as she wept in front of TV cameras. 

Jeff Ostrowski contributed reporting. 

Update: This story has been updated to reflect that Restore Construction Group worked on the Champlain Towers East (8855 Collins Avenue), not the Champlain Towers North (8877 Collins Avenue), both of which are sister buildings to the Champlain Towers South.