The death toll rose to 18 in the condo building’s collapse, the Miami-Dade County mayor said.

The known death toll in last week’s collapse of a condominium building in Surfside, Fla., rose by six, to 18, and now includes children, as the authorities said more bodies were recovered from the rubble on Wednesday.

At a news conference on Wednesday evening, Mayor Daniella Levine Cava of Miami-Dade County said as many as 145 people remained missing nearly a week after the desperate search for survivors began. The bodies of two children, ages 4 and 10, were found on Wednesday.

“Any loss of life, especially given the unexpected, unprecedented nature of this event is a tragedy,” Ms. Levine Cava, visibly emotional, said at the news conference, the second of the day. “But the loss of our children is too great to bear.”

Even as days passed with little hopeful news, officials said they remained focus on comforting families and continuing to search for any survivors in the rubble.

“While there’s an overwhelming amount of grief, there’s just still the apprehension about not knowing for sure,” Gov. Ron DeSantis of Florida said Wednesday.

Inclement weather has continued to hamper the search effort, and Florida officials have requested extra help in case some state personnel are needed to respond to any future hurricanes. A system that could become a tropical storm has developed in the Atlantic Ocean, and officials said they were developing contingency plans as the search effort continued, although no impact was expected before Saturday.

“We have done this before where we have responded to multiple emergencies in the state at the same time,” said Kevin Guthrie, the director of the Florida Division of Emergency Management.

As the search in Surfside has dragged on, volunteers and trained rescue teams from across the country and beyond have gathered. Local leaders also warned of those trying to take advantage of the disaster, including by creating fraudulent online fund-raising accounts.

Search teams said on Tuesday that they had removed more than three million pounds of debris from the wreckage since Thursday, when a section of the oceanfront complex caved in during the early-morning hours.

Yet as the pile of concrete, steel and personal effects slowly began to diminish, new warning signs pointing to the building’s critical failure began to emerge. A letter that the president of the condominium association wrote to residents in April publicly surfaced, revealing deep concerns about the building’s condition less than three months before it gave way.

Miami-Dade County officials have declined to release a list of names of the nearly 150 people who remain unaccounted for. Many of their families remain gathered in South Florida, where they receive updates from officials and are able to ask them questions.

Magaly Delgado, 80, who left Cuba in the early 1960s, fearing she would speak out against the revolution, was among the missing, said her daughter Magaly Ramsey. On Monday afternoon, she was allowed to visit the site of the tragedy, where she decided that her mother had not survived.

“I’m a very logical, tough woman,” said Ms. Ramsey, who had a question for a rescue official nearby. Can a body just disintegrate?

The answer, Ms. Ramsey recalled in an interview, was “yes.”

First responders continued their search on Wednesday, for the unaccounted victims from Champlain Tower South in Surfside, Fla.Credit...Maria Alejandra Cardona for The New York Times

There may come a time when crews combing through the rubble in Surfside, Fla., make the painful decision that their rescue mission must shift to recovery. But for now, local officials remain emphatic that they could still find survivors in the wreckage.

“It’s going to be a rescue for the indefinite future,” Mayor Charles Burkett of Surfside said Wednesday in an interview. “We’re not going to give up on anyone, and we are leaving nobody behind.”

Days have passed in South Florida without good news. No survivor has been pulled from the rubble of Champlain Towers South since the first hours after the collapse last Thursday. The known death toll rose to 16 on Wednesday, with more than 140 people still unaccounted for. And rescue crews continued to contend with bad weather and difficult conditions.

Still, Michael J. Fagel, an emergency planner who was a scene-safety and logistics officer after the 9/11 attacks in New York City and the 1995 bombing in Oklahoma City, said it remained prudent to focus on rescue efforts. People have survived for several days after building collapses in other countries, including Haiti and Mexico.

“Nobody wants to stop rescue. Nobody. They want to rescue for every moment they possibly can,” Dr. Fagel said. “Nobody wants to do recovery. Because recovery means that, sadly, that we haven’t been able to save more people.”

Chief Alan Cominsky of Miami-Dade Fire Rescue said Wednesday that teams working in the debris continued to listen for voices and navigate around heavy concrete slabs. He described it as “an extremely, extremely difficult situation,” but said it was “absolutely still a search and rescue mission.”

“The assignment is the same as it’s always been,” said Chief Cominsky, who described trying to find survivors by using dogs, sonar equipment and video.

Dr. Fagel said the presence of appliances and other large household items in the tower might create more so-called void spaces where people can live after a collapse.

“The hope is that as the crews meticulously thread through the building inch by inch, there’s an opportunity they may find a viable person,” he said.

But Dr. Fagel also described the difficult decision after 9/11 to eventually start transitioning to a recovery operation.

“That’s very debilitating for the families, the crews, hoping against hope,” he said. “I can guarantee you right now that the incident management team, the overhead teams, they’re certainly looking at every angle and hoping they don’t have to make that call.”

Stacie Fang, 54, was the first victim identified in the condo collapse. She was the mother of Jonah Handler, a 15-year-old boy who was pulled alive from the rubble in a dramatic rescue as he begged rescuers, “Please don’t leave me.”

Antonio Lozano, 83, and Gladys Lozano, 79, were confirmed dead by Mr. Lozano’s nephew, Phil Ferro, the chief meteorologist on WSVN Channel 7 in Miami. Mr. Ferro wrote on Instagram: “They were such beautiful people. May they rest in peace.”

Luis Andres Bermudez, 26, lived with his mother, Ana Ortiz, 46, and stepfather, Frank Kleiman, 55. Mr. Bermudez’s father confirmed his son’s death on social media, writing in Spanish: “My Luiyo. You gave me everything … I will miss you all of my life. We’ll see each other soon. I will never leave you alone.”

Manuel LaFont, 54, was a businessman who worked with Latin American companies. His former wife, Adriana LaFont, described him as “the best dad.” Mr. LaFont’s son, 10, and daughter, 13, were with Ms. LaFont when the building collapsed.

Leon Oliwkowicz, 80, and Cristina Beatriz Elvira, 74, were from Venezuela and had recently moved to Surfside, according to Chabadinfo.com, which said they were active in the Orthodox Jewish community in greater Chicago, where one of their daughters lives.

Marcus Joseph Guara, 52, lived with his wife, Ana, and their two daughters, Lucia and Emma, all of whom remain missing. He was remembered as a kind and generous man, a godfather to twins and a fan of hard rock music.

Hilda Noriega, 92, was a longtime resident of Champlain Towers South who enjoyed traveling and whose family described her “unconditional love.” Hours before the collapse, she attended a celebration with relatives.

Also killed in the collapse was Michael David Altman, 50.

— The New York Times

Near the site of the Champlain Towers South collapse in Surfside, Fla., on Monday.Credit...Scott McIntyre for The New York Times

As crews sift through the rubble of the collapsed condominium building near Miami in hopes of rescuing more residents, another effort is underway to support the survivors who made it out of the apartment building.

Thousands of dollars have poured in to Surfside, Fla., to support not only the families of those who are missing in the wreckage of Champlain Towers South, but the survivors who are now grappling with the loss of their homes and most, if not all, of their possessions. As of Wednesday morning, the Chesed Fund, run by the Shul of Bal Harbour, had raised more than $1.2 million.

“Most of the people I met left with the shirts on their backs,” said Michael Capponi, the founder of Global Empowerment Mission, a nonprofit humanitarian organization that has partnered with BStrong, a foundation supported by Bethenny Frankel, the entrepreneur and reality television star, to help support the survivors of the apartment collapse.

“You’re dealing with people who have worked their whole lives to pay a mortgage,” he added. “Now it’s gone.”

In a warehouse in Doral, Fla., he and volunteers put together an assembly line of cardboard boxes: kits with toothbrushes and toothpaste, phone chargers, blankets, pillows, shaving cream, vitamins, carefully wrapped in branded packaging and sleek fabric cases to make it easy to transport. The organization also aims to distribute $180,000 in gift cards by the end of the week, to help families buy food and supplies while they figure out their next steps.

The next challenge has been temporary housing: while hotels have opened rooms to help support reunification centers, Mr. Capponi and other organizations are working to find temporary apartments — ideally already furnished and open for at least a month — that will allow the survivors to have their own home outside of a hotel. Some need to be near a temple, others wish to remain close to the collapsed building as they wait anxiously for news about their neighbors, friends and loved ones.

Gov. Ron DeSantis spoke at a news conference in Surfside, Fla., on Monday.Credit...Scott McIntyre for The New York Times

Since the partial collapse of a condominium tower in the Miami area on Thursday, Gov. Ron DeSantis of Florida has been a frequent presence at the site, and has spoken of his visits with rescue workers, federal and local officials and family members in Surfside, Fla.

Mr. DeSantis, considered a rising political star in the Republican Party, has also been a fixture at the Surfside news briefings, speaking to a national and even international audience and further expanding his profile beyond Florida.

“To be able to see the real raw pain and the emotion that this has caused, it’s not something that we are ever going to forget,” he said at a Wednesday morning media briefing, noting that the rescue effort was “the largest deployment in a non-hurricane-related response in the history of the state.”

He also added that he privately met with some of the family members who were waiting to hear about their loved ones, as rescue crews spent a seventh day digging through the rubble for missing residents.

Mr. DeSantis, who has been discussed as a potential candidate for president as early as 2024, is far from the only politician to have visited the site. Florida’s two senators, Rick Scott and Marco Rubio, both Republicans, and Representative Debbie Wasserman Schultz, a Democrat, have also visited. So, too, has a parade of city and county elected officials from both parties, many of whom have promised investigations into the cause of the collapse.

President Biden was set to join that list on Thursday, setting up one of the few moments where Mr. DeSantis and Mr. Biden may be in lock step ahead of the 2024 election. While Mr. DeSantis has repeatedly been critical of Mr. Biden and his administration’s response to the coronavirus pandemic and the influx of migrants at the southwestern border, he has publicly voiced appreciation for the president’s support after much of the building collapsed.

The two men spoke after Mr. Biden approved an emergency declaration for Miami-Dade County, which allowed the Federal Emergency Management Agency to coordinate relief efforts and provide additional resources.

Mr. DeSantis also swatted away a question this week about his decision to deploy Florida law enforcement officers to the southwestern border as rescue efforts were underway in Surfside, dismissing the connection as “wrong and political.”

Flowers and messages of support on a makeshift memorial in Surfside, Fla., on Monday.Credit...Scott McIntyre for The New York Times

After nearly a week of searching the wreckage of Champlain Towers South, more than 140 people remain unaccounted for.

But officials have not yet named those who are considered missing, forcing reporters and other observers to rely on the social media posts of family members or the laminated pictures tied to a fence at a nearby memorial site.

Mayor Daniella Levine Cava of Miami-Dade County has referred to concerns about confidentiality, and said on Wednesday that the authorities remained in the process of auditing their list of missing people to get rid of potential duplicates. Officials have named most of the 16 people known to have died in the collapse.

When a relative or friend calls the county’s hotline to report someone who might be missing, state and local authorities pursue leads, review them and open a case. But some may have called about the same person, sometimes without apartment numbers. Some people may be listed with both their English and Hebrew names.

“We have people calling in from everywhere with hunches,” Ms. Levine Cava said.

The decision to not publicly release the list of the missing is a stark contrast compared to other disasters like the Paradise fire in Northern California in 2018. More than 1,000 people were initially listed as missing.

The sheriff there added every person who was described as missing in a 911 call and warned that the list would fluctuate. The hope was that people who checked in with the sheriff’s office would learn that someone was looking for them.

Doral, the Florida city where a former Surfside building official most recently worked, is now reviewing all of the official’s work out of “an abundance of caution,” a spokesman for the city said Wednesday.

Ross Prieto, the former chief building official at Surfside, had received a critical engineering report about the Champlain Towers South nearly three years before the condo building collapsed. Records show that he attended a condo association meeting at the time, and said the building looked fine.

Since May, Mr. Prieto has worked as the interim building official in the nearby city of Doral. He was employed by a contractor which billed the city $120 an hour for Mr. Prieto’s services.

In his seven weeks working for the city, Mr. Prieto reviewed eight construction projects, which are now under review, said Rey Valdes, a spokesman for the city.

“In an abundance of caution, we are going to review everything he did,” Mr. Valdes said. “We don’t suspect he did anything wrong, nevertheless, given the circumstances we are dealing with, we are going to review everything he did to make sure it’s in line with state law and municipal code.”

Mr. Prieto has been on leave since Monday. He has not responded to requests for comment.

Less than three months before the collapse of the Champlain Towers South condo in Surfside, Fla., the president of the condominium association warned in a letter that the damage in the building had “gotten significantly worse” since it was highlighted in a 2018 inspection.

The letter was written to residents by Jean Wodnicki, president of the association’s board of directors, explaining why a list of extensive construction projects were worth a $15 million special assessment that residents were being asked to pay.

Along with the 2018 inspection, which warned of “major structural damage,” the letter, a copy of which The New York Times obtained, adds to a growing body of evidence that engineers had raised alarms about serious flaws in the building months and even years before the catastrophic building failure, which killed 12 people and left 149 unaccounted for.

Ms. Wodnicki could not immediately be reached for comment.

That 2018 inspection warned that concrete damage would “multiply exponentially” in the coming years, Ms. Wodnicki wrote in the letter, which was earlier reported by USA Today and The Wall Street Journal. The engineer who prepared that initial report, Frank Morabito, carried out “a much more detailed survey of the property” and found signs that this acceleration was indeed already happening. “When you can visually see the concrete spalling (cracking), that means that the rebar holding it together is rusting and deteriorating beneath the surface,” Ms. Wodnicki wrote.

She explained that these signs of growing damage were why the estimated costs of repair had jumped by some 60 percent since that 2018 inspection. “The concrete deterioration is accelerating. The roof situation got much worse,” she wrote, adding, “New problems have been identified.”

“A lot of this work could have been done or planned for in years gone by,” she wrote in the letter. “But this is where we are now.”

Sharon Schechter, a renter of an 11th-floor unit in the condo tower, told CNN on Tuesday night that cracks in the building and the presence of water in the parking garage had been conspicuous. She said that she was in bed when she felt something like an earthquake, and that when she looked out the glass doors of her terrace, the landscape was unrecognizable.

“I saw nothing, and I’m saying to myself, ‘Where is my building?’” she said. “I thought I was dreaming. I thought I was in a nightmare.”

Coco remained inside when her owners evacuated the intact part of the building.

Above the rubble in Surfside, Fla., on the still-standing fourth-floor balcony of the collapsed condo building, firefighters this week left food and water for a cat named Coco.

A Miami city commissioner, Ken Russell, had initiated the search for pets left in the building when he heard from someone who is friends with Coco’s owners, who safely evacuated on Thursday morning.

When Coco’s owners, an 89-year-old woman and her daughter, were led out of the building by firefighters, their dog, Rigatoni, followed. But Coco remained inside the apartment.

“Clearly the priority is loss of human life and rescuing people,” Mr. Russell said. But he added that those who made it out of the building safely were distressed after losing their possessions and their pets, and that rescue workers could assist “them with reunification or at least giving them the peace of mind that we are trying to help at least feed their animals.”

Chief Alan Cominsky of Miami-Dade Fire Rescue said on Tuesday that his team did not find any indication of more pets still in the building.

The organization Friends of Miami Animals set up a hotline on Tuesday for residents of the collapsed building looking for assistance in rescuing pets. The hotline number is 833-366-2642.

— Sophie Kasakove