A Florida high rise that collapsed early Thursday was determined to be unstable a year ago, according to a researcher at Florida International University.
The building, which was constructed in 1981, has been sinking at an alarming rate since the 1990s, according to a 2020 study conducted by Shimon Wdowinski, a professor in the Department of Earth and Environment at Florida International University.
When he saw the news that the condo had collapsed, he instantly remembered it from the study, Wdowinski said.
“I looked at it this morning and said ‘Oh my god.’ We did detect that,” he said.
Wdowinski said his research is not meant to suggest any certainty about what caused the collapse of the condominium. The building was sinking at a rate of about 2 millimeters a year in the 1990s, and the sinking could have slowed or accelerated in the time since.
In his experience, Wdowinski said even the level of sinking observed in the 1990s typically results in impacts to buildings and their structures. He believes that very well could have been the case for the Champlain building in the 1990s, based on his findings.
“It was a byproduct of analyzing the data. We saw this building had some kind of unusual movement,” Wdownski said.
But Daniel Deitch, who served as Surfside’s mayor from 2010-2020, warned against drawing conclusions too soon.
“This is an extraordinarily unusual event and it is dangerous and counterproductive to speculate on its cause,” he said.
Workers continued to sort through the rubble Thursday afternoon. Officials have said 35 people were rescued and confirmed at least two deaths, saying they expect the death toll to rise. At least 99 people remained unaccounted for.
According to Surfside Town Commissioner Eliana Salzhauer, one thing is sure: “This was not an act of God. This was not a natural disaster. Buildings don’t just fall.”
Water damage and cracks
The town of Surfside requires commercial and multi-family buildings to be recertified every 40 years. The process involves electrical and structural inspections for a report to be filed with the town. It was underway for the building but had not yet been completed, town officials said Thursday.
Salzhauer said no serious complaints about the building had been brought to the town’s attention.
“If a building had serious problems we would certainly know about it,” she said.
A 2015 lawsuit that alleged building management failed to maintain an outside wall, resulting in water damage and cracks. The owner who filed that suit, Matilde Feinstein, had previously sued over the same issue, she said in a court filing. The management company paid for damages in the earlier case, she said.
Cracked walls or shifting foundations can be clues that sinking has affected the stability of a structure, according to Wdownski.
The city needs to invest in technology that can determine which buildings are at risk of collapse due to geologic processes, according to Keren Bolter, a Florida-based geoscientist at the engineering firm Arcadis who has advised the Federal Emergency Management Agency on hazard mitigation.
“It’s very sad that people are forced to be reactive. We’re constantly putting out fires. I think there’s a systemic problem we have,” she said. “Investing in preventative measures instead of reactive responses saves lives, money and time.”
Monitoring via satellites, drones and other means are being increasingly used to understand where Florida is sinking and which buildings might be at risk, according to Ryan Shamet, a professor of engineering at the University of North Florida. But those efforts vary by jurisdiction and depend on whether structures are privately or publicly owned, he says. Aside from the analysis done at the time of construction, monitoring is generally not done proactively, he said.
”Structural health monitoring is already there,” Shamet said. “But it’s hard because we don’t have the resources yet to monitor every single structure. You kind of have to know if there’s an issue first before you start monitoring it.”
Impact of sea level rise and flooding
Over the past several years, Wdowinski and his team have researched which parts of the Miami area are sinking, primarily to identify where sea level rise and flooding could have the most impact. They obtained historical data from European satellites, which mapped the area by bouncing signals down to the ground and back to identify shifting elevations.
They published the results in April 2020.
The data, originally collected between 1993 and 1999, showed that most of the Miami area was not sinking appreciably, save for a few hot spots around the region. Wdowinski says most of those occurred in the western part of Miami, where the elevation is lower. The level of sinking at the Champlain condo was unusual, he said.
Wdownski said he doesn’t believe that anybody in the city or state government would have had a reason to be aware of the findings of the study. The bulk of it focused on potential flooding hazards, not engineering concerns. The study’s mention of the “12-story condominium” was relegated to a single line.
“We didn’t give it too much importance,” Wdowinski said.
He added that the incident has made him think of the potential utility of using such data to identify areas of potential structure risk now and in the future.