SURFSIDE, Fla. — A woman who had just moved back from New York, where she'd recovered from a bout with covid-19. A plastic surgeon from Argentina and his partner who had flown to South Florida to get vaccinated against the coronavirus. A couple whose adult daughter had just arrived Wednesday night from Los Angeles for a visit.

Now, after the building suddenly pancaked in the first hours of Thursday, at least 99 people were missing, presumed to be in the rubble, feared to be crushed under the unfathomable weight of a 55-unit wing of the condominium tower.

They were aging denizens of Miami Beach and affluent Latin Americans whose condominiums by the sea were part-time homes. They were snowbirds who hadn’t quite made it back north for the summer and year-round residents hunkered down for South Florida’s stickiest months. They lived in a 40-year-old beachfront building that offered views of the ocean and the Intracoastal Waterway, of sunrise and sunset.

Chani Nir's family were among the first ones out of the Miami-Dade condo building after it collapsed on June 24. She feels lucky to be alive. (James Cornsilk, Drea Cornejo/The Washington Post)

The missing included 10 citizens of Argentina, six from Paraguay, six from Colombia and four from Venezuela, according to those countries’ diplomats and news reports. Early reports indicated up to 20 citizens of Israel were also missing, but officials in Israel said they believe the number is lower.

The Shul, one of five synagogues within walking distance of the tower, released a list of 10 of its members who vanished in the collapse.

The sister of Paraguay’s first lady and her husband and children were missing in the collapsed building, in one of two units that the family owned. So was Arnie Notkin, a legendary PE teacher and coach at Miami Beach schools. So was Brad Cohen, an orthopedic surgeon who lived on the 10th floor.

The building crumpled at 1:30 a.m. It fell in less than 10 seconds. The sound was horrific. The earth shook. Many of the residents, most presumably asleep at that hour, have not been heard from.

On Wednesday afternoon, Jenny Urgelles texted with her mother, Mercedes, and spoke by phone with her father, Ray, both in the pharmacy business in South Florida.

“Everything was fine,” she said. Then, early Thursday, after she heard about the collapse, she called her parents. Their phones went straight to voice mail. By late Thursday, she was still in an information vacuum.

“We haven’t gotten anything,” she said. “They’re not allowing anyone to go down there,” to the building where she had lived, where she visited often, using the pool, walking the beach.

The people in charge of the search and, they hoped, the rescues did not even know exactly how many victims they were looking for. Relatives and friends gathered on nearby streets and frantically searched social media, desperate for any word about their loved ones.

Julio Cesar Velasquez, 67, and Angela Maria Velasquez, 60, lived in Unit 304 for nearly a decade, according to their son, David Velasquez. Julio Cesar is retired; his wife owns a small men’s clothing shop called Fiorelli in Weston, 35 miles away. Their daughter Theresa, an executive at the entertainment company Live Nation, had just arrived from Los Angeles on Wednesday night to visit her parents.

“She’s an icon there in Weston,” said Pilar Martinez, 52, a friend of the family for over 30 years. “Everybody knows who she is and that store.”

Martinez said she spent all of the major holidays with the Velasquezes. They arrived to the United States from Colombia in their teens and don’t have many family members here, so close friends like Martinez became family.

“She’s like my big sister,” Martinez said of Angela Maria.

Martinez waited all day at the family reunification center, hoping the three would arrive. She checked with all the local hospitals, she said, but did not see their names. As the sun set Thursday evening, Martinez left the center to meet up with David, who flew into South Florida from New York.

Champlain Towers was typical of the oceanfront halfway up the barrier island of Miami Beach — mid-rise buildings erected in the 1980s to serve the older folks who were moving up from then-decaying South Beach and down from the frigid North. Over the next 20 years, the mix of residents shifted as affluent Latin Americans moved their money — and, for at least a few months each year, themselves — to South Florida.

Real estate agents who do business in the building said about 70 percent of the units in the towers were occupied. Listings on vacation rental sites indicate that many of the apartments are rented out to tourists and other visitors for at least part of the year.

Andres Galfrascoli, 45, a plastic surgeon from Argentina, had borrowed a friend’s apartment in the tower. He had made the trip with his husband, theater director Fabián Núñez, 55, and their just-adopted daughter, Sofia, age 6, to get vaccinated against the coronavirus.

Relatives said that Galfrascoli, Nunez and their daughter were missing.

Family members, friends and colleagues gathered at a family reunification facility set up at Surfside’s community center. There, the hours passed glacially with no news. Phone batteries drained as those who waited searched social media feeds for contact with anyone who might know something.

Adriana Chi sat on the sidewalk, trying to coordinate with friends and family to get information on her brother, Edgar Gonzalez, a 45-year-old attorney who was in his unit in the south tower with his wife and daughter, both of whom were rescued and taken to Jackson Memorial Hospital in downtown Miami. The wife and daughter were in stable condition after surgery, but Chi had nothing on her brother.

“Nobody’s heard from him,” Chi said. “I’m just trying to find somebody who can tell me if they saw him or where he is.”

Luz Marina Pena carried a photograph of her aunt, 77-year-old Marina Azen, who lived on the fourth floor. Azen, who suffered from asthma and lived alone, lived in the building for 20 years.

“I’m praying for a miracle,” Pena said.

Betsy Gonzalez rushed to a hospital Thursday morning, trying to find her niece Anaely Guara, 41, Guara’s husband, Marcos, 55, and the couple’s daughters, ages 4 and 11. Gonzalez was told they were not there.

Anaely Guara was born in Cuba and came to the United States as a teenager, Gonzalez said. She later met Marcos, who worked in the hotel business. They moved into the Surfside building less than a year ago, drawn to the proximity of the ocean.

“They loved it here,” Gonzalez said.

Marcos’s brother, Manuel Guara, said it did not occur to him that his brother’s building was the one that collapsed until his wife realized the addresses matched. He immediately drove to the site, his heart sinking when he saw the rubble. He spent 12 hours searching for his family, returning home with no closure.

Rabbi Eliot H. Pearlson of Temple Menorah, a synagogue near the collapsed building, said some of the missing had flown in for two funerals: one of an elderly woman and the other of a 51-year-old man.

In Paraguay, the foreign minister said that at least five members of President Mario Abdo Benítez’s family were in the Champlain Towers building when it collapsed. The missing relatives are Sophia López Moreira, a sister of the South American country’s first lady, Silvana López Moreira; Sophia’s husband, rancher Luis Pettengill; and the couple’s three young children. An employee of the family, Lady Luna Villalba, was also missing.

In Miami, Paraguayan consular workers fanned out to the city’s hospitals hoping to locate the members of the presidential family. No one was found.

Debra Golan, a Realtor, has shown the building to potential buyers over the course of her career. Surrounded by exclusive, upscale condos, this building is more middle-class, she said, with a wide range of tenants — from young families to retirees to empty nesters. But her greatest connection to the place was not through work — it was through one of her closest friends, Estelle Hedaya.

Hedaya, 54, is an operations director at the Continental Buying Group and Preferred Jewelers International. After work she would sometimes write essays on her blog, Follow the Toes, about her diet journey, favorite foods and spas.

She is also a big fan of cats — especially Golan’s cat, Izzy.

“She’s in love with my cat,” Golan said. “She will literally babysit the cat when we go on vacation. She’s super cute.”

Golan and Hedaya first met in college in New York City — where Hedaya was born and raised — and became fast friends. As life pulled them along different paths, they naturally drifted apart until Hedaya moved to Florida a few years ago and the two women reconnected.

Wednesday evening, they spoke for the first time in a while, spending over an hour on the phone.

“We were just catching up on life. It was one of those conversations — amazing until you’re too tired to continue,” Golan said.

They hung up at 10:25 p.m. Wednesday night.

“That’s the last we’ve heard of her,” she said. “I called her a million times today and she doesn’t pick up, you know what I mean?”

Fisher, Hawkins and Foster-Frau reported from Washington. Julie Tate, Jennifer Jenkins and Maria Paul in Washington and Christine Armario and Anthony Faiola in Surfside contributed to this report.