SURFSIDE, Florida (AP) -- Elected officials pledged Tuesday to conduct multiple investigations into the collapse of an oceanfront Florida condo tower, vowing to convene a grand jury and to look closely "at every possible angle" to prevent any other building from experiencing such a catastrophic failure.
Miami-Dade County Mayor Daniella Levine Cava said she and her staff will meet with engineering, construction and geology experts, among others, to review building safety issues and develop recommendations "to ensure a tragedy like this will never, ever happen again."
State Attorney Katherine Fernandez Rundle said she will pursue a grand jury investigation to examine factors and decisions that led to Thursday's collapse of the 12-story Champlain Towers South in Surfside. Another victim was recovered Tuesday, bringing the confirmed death toll to 12, with 149 people unaccounted for.
Even as officials looked to the future to determine the cause of the collapse, they were resolute in vowing to continue the effort to find survivors.
On the sixth day of a painstaking search, Gov. Ron DeSantis evoked a well-known military commitment to leave no one behind on the battlefield and pledged to do the same for the people still missing in the rubble.
"The way I look at it, as an old Navy guy, is when somebody is missing in action, in the military, you're missing until you're found. We don't stop the search," DeSantis said at a news conference.
"I think that's what is happening. Those first responders are breaking their backs trying to find anybody they can. I think they are going to continue to do that. They've been very selfless. They've put themselves at risk to do it."
Surfside Mayor Charles Burkett cited the case of a woman who was found alive 17 days after a garment factory collapsed in 2013, killing more than 1,000 people in Dhaka, Bangladesh.
"No one is giving up hope here. ... We are dedicated to getting everyone out of that pile of rubble," Burkett said.
Also Tuesday, the White House announced that President Joe Biden and first lady Jill Biden would travel to Surfside on Thursday.
Martin Langesfeld, whose sister, 26-year-old Nicole Langesfeld, is missing in the collapse, also expressed hope that there are still survivors.
"We're not alone in this. There's hope. I really believe miracles do happen. Things like this have happened around the world," he said during a vigil Monday night on the beach near the collapsed building.
The collapse has drawn scrutiny of the safety of older high-rise buildings throughout South Florida. Cava ordered a 30-day audit on whether buildings 40 years old or older are complying with a required recertification of their structural integrity, and that any issues raised by inspections are being addressed.
On Tuesday, the mayor said building inspections have found four balconies in one building in Miami-Dade County that "must be immediately closed due to safety concerns."
Previous grand juries in South Florida have examined other large-scale disasters, such as the 2018 collapse of a pedestrian bridge at Florida International University, which killed six people. That investigation is ongoing.
Criminal charges in such matters are possible, such as the third-degree felony murder and manslaughter charges brought in the 1996 crash of ValuJet Flight 592, which killed 110 people in the Everglades.
Work at the site has been deliberate and treacherous. Debris fell onto the search area overnight from the shattered edge of the part of the building that still stands. That forced rescuers to mark a "don't go beyond here" line and focus their efforts on parts of the debris pile that are farther from the structure, Burkett told Miami television station WSVN.
Kevin Guthrie of the Florida Division of Emergency Management said his agency requested an additional search team. He said state officials want to rotate some of their teams out so they can be on hand in case of severe weather in the coming days.
Several members of an Israeli rescue team worked partly on hands and knees Tuesday over a small section of the rubble, digging with shovels, pickaxes and saws. They removed debris into buckets that were dumped into a metal construction bin, which was periodically lifted away by a crane. The crane then delivered an empty bin.
Late in the afternoon, rescue officials sounded a horn for a second time during the day's work, signaling an approaching storm with lightning. Workers temporarily evacuated.
Authorities said it's still a search-and-rescue operation, but no one has been found alive since hours after the collapse on Thursday.
The pancake collapse of the building left layer upon layer of intertwined debris, frustrating efforts to reach anyone who may have survived in a pocket of space.
Authorities meet frequently with families to explain what they're doing and to answer questions. They have discussed how DNA matches are made to help identify the dead, how next-of-kin will be contacted and explained in "extreme detail" how they are searching the mound, the mayor said.
With that knowledge, Cava said, families are coming to their own conclusions.
"Some are feeling more hopeful, some less hopeful, because we do not have definitive answers. We give them the facts. We take them to the site," she said. "They have seen the operation. They understand now how it works, and they are preparing themselves for news, one way or the other."
Rachel Spiegel, whose 66-year-old mother, Judy Spiegel, is missing, said Tuesday that she was hoping for a miracle, but she also wrote about looking beyond the tragedy.
"Our mom Judy was the glue that kept our family together. All of the family mementos, photos, clothing and heirlooms our father and mother have collected over the past 65 years were lost in a matter of seconds," Spiegel wrote in a message about setting up a fund for charities on behalf of her mother. "As we continue to search for meaning in this catastrophe, we must also look to the future and rebuild."
In a text message exchange with The Associated Press, she added, "Please keep praying for a miracle."