Threat looms from remaining building at collapse site as authorities weigh next moves
A confluence of concerns about the stability of the remaining structure at the site of the Champlain Towers South collapse forced officials to call back rescue crews that had been working nonstop over the last week painstakingly removing debris and foraging trenches in desperate attempts to locate survivors.
Miami-Dade Fire Rescue Chief Alan Cominsky confirmed the development during a press briefing on Thursday morning. The agonizing decision, he said, was made just after 2 a.m. Cominsky described the threat of a large concrete column hanging over a subterranean parking area, which has moved six to 12 inches. He added that crews were also alerted to widening cracks and “slight movement” in a concrete slab on the southern side of the building.
Miami-Dade Fire Rescue announced on Twitter at about 6 p.m. Thursday that work had resumed. Miami-Dade Mayor Daniella Levine Cava later said that the work was continuing in areas that are safe. The pause in work lasted about 15 hours, resuming at 4:45 p.m., Levine Cava said.
In regard to the “likely demolition” of the remaining structure, Levine Cava said, “this is a decision that we need to make extremely carefully and methodically.”
Miami-Dade Fire Chief Alan Cominsky said work resumed on three of nine grids, and officials will reassess the status of the site later.
High-tech monitors aimed at the tenuous pile of debris were responsible for making rescue workers aware of the dangerous shifts. Moments later, they were forced to lower cranes and pull back crews under the darkness of the early morning.
It was the first time rescue workers paused their efforts for a significant amount of time, an engineer with the federal response told family members of the missing Thursday, and another example of the structural challenges involved in trying to find survivors in the midst of a collapsed building with another portion of a tower looming above.
Scott Nacheman, an engineer with the Federal Emergency Management Agency, said the debris pile that’s the focus of the rescue efforts also is bracing the remaining 12-story structure that poses the top danger for workers on the ground. Teams monitoring the remaining structure discovered movement overnight in the tower, as the previously stable debris pile began shifting with the presence of heavy machinery that wasn’t present in the early days of the effort.
“We were very concerned, based on the measurements we were getting,” Nacheman said, according to a video of the private briefing posted on social media by one of the relatives. The Miami New Times first reported on the video’s contents. “It basically showed the building had moved.”
He said the overnight pause had authorities weighing demolition — a move that would swap the risk of falling debris for the complication of adding tons of new wreckage to a scene after a week of clearing rubble.
In a demolition scenario, Nacheman said, “we’re going to be adding a tremendous amount of material on top of things we’ve already cleared. ... It doesn’t necessarily speed up the process. It slows down the process.”
Daily downpours are adding to the engineering headaches as well. Authorities have already said rain hampers the effort to find survivors and victims, given the value of biological material on debris helping locate people beneath the materials. The rain also is making the debris and remaining structure less stable, given the additional weight, Nacheman said.
“Rain is entering an open building,” he said. That’s “saturating, to some extent, the concrete, but also the contents of that building,” he said.
Surfside Mayor Charles Burkett said Thursday that demolition talks are underway with Gov. Ron DeSantis and Levine Cava. Burkett said the final decision rests with Levine Cava, and he’s asked DeSantis for state resources for the potential demolition.
“If the building is a problem,” Burkett said, “then we need to take it down.”
‘Most complicated site I’ve ever seen’
Elad Edri, the deputy commander for the Israeli search-and-rescue team at the site, told the Miami Herald after the press briefing that there was nothing to do but wait for the site to stabilize.
Edri was not there Thursday morning when local crews made the decision to halt operations after noticing the shifts, but he described the collapsed wreckage as “the most complicated site I have ever seen in my life.”
“The collapse is very, very unique,” he said. “The building was collapsed inside itself, and it collapsed in four different phases. And each phase collapsed above the former one. So we are dealing with a few thousand layers and floors, one above another.”
Without knowing the exact details of the movement in the structure, it was hard for structural engineers to offer suggestions on what could be done to help stabilize it and continue working.
Raul Schwerdt, a Broward County-based engineer, said that one solution might be building a tunnel under the protection of scaffolding, but that plan could be complicated if the structure was sagging or moving sideways.
“I don’t think we’ll have an answer yet, until we move all the concrete,” he said.
Another engineer, Mohammad Ehsani, has invented a product to help reinforce broken columns called QuakeWrap. Ehsani said that not all damage is the same, and the options for rescue workers would depend on the state of the structure.
“Sometimes, if you have just one column that is leaning and broken, it can be shored up,” he said. “If you have a dangling column that is swinging, it could be a different scenario.”
‘No impact’ from Biden visit
In response to concerns from family members of the missing that President Joe Biden’s Thursday also could be slowing rescue operations, Levine Cava said there was “no impact” from the visit, and that the change was made solely due to structural concerns.
“We’re deeply grateful that our community remains a top priority for the president as he continues to provide the full support of the federal government,” she wrote in a tweet Thursday morning.
Gov. DeSantis said that state Department of Transportation engineers were helping Miami-Dade Fire Rescue get “different options on how to handle this.”
“Obviously we believe that continuing searching is something that’s very important,” he said.
Cranes lowered before sunrise
Before sunrise Thursday, two cranes were lowered at the site of the Surfside condo collapse after authorities halted debris clearing and search and rescue over concerns the remaining structure of Champlain Towers South would topple.
After 2 a.m., multiple police officers and rescue personnel said they were hearing warnings that new instability could lead to another collapse.
That led to clearing people from the area around the rescue operation, they said. A crane that had been used to move debris all evening was idle as 3 a.m. approached. By 5 a.m., that crane and another were no longer visible from the nearby media area.
Hours later, Nacheman, the FEMA engineer, described the situation as an unwelcome milestone in an effort that entered its second week that morning.
“This is the first pause that’s occurred since the initial fire trucks rolled up on the scene,” he said.
The two buildings on either side of the Champlain South were evacuated shortly after the June 24 collapse.
Just before 9 a.m., Miami-Dade Fire Rescue hadn’t officially confirmed the work stoppage, but search and rescue team member Maggie Castro said structural engineers that lead the Urban Search and Rescue team members use extremely sensitive tools that monitor any movement in the building, down to millimeters.
“It’s very accurate,” she said.
One of the tools used is called a crack gauge, which monitors any change in cracks on flat surfaces or corners.
They also use an item called a total station, which measures vertical and horizontal angles and images by analyzing the slope between it and a specific point.
Surfside Mayor Burkett said from the day of the collapse, rescuers knew the intact portion of the building was unstable.
“They’ve been told this thing can fall at any time,” Burkett told the Miami Herald.
He said rescue crews “plowed ahead” without looking back.
“Let’s get some badges that say hero,” he said.
Miami Herald Staff Writers Martin Vassolo, Samantha J. Gross , Sarah Blaskey and Mary Ellen Klas contributed to this report.
This story was originally published July 1, 2021 at 11:16 AM.
