The confirmed death toll rose to four with 159 people still unaccounted for as the search for survivors went on at the partially collapsed Champlain Towers in Surfside, Florida, on Friday.

Among the missing were a couple from Argentina and their young daughter; a retired Miami-area teacher and his wife; Orthodox Jews from Russia; several Israelis; the sister of Paraguay’s first lady and other people from South America.

Much of the 12-floor Champlain’s beach side sheared off for unknown reasons, pancaking into a pile of concrete and metal more than 30 feet high.

Three bodies were pulled from the rubble overnight, bringing the death toll to four, Miami-Dade Mayor Daniella Levine Cava said on “Good Morning America” on Friday. Officials feared that number could skyrocket. Eleven injuries were reported, with four people treated at hospitals.

“These are very difficult times, and things are going to get more difficult as we move forward,” Miami-Dade Police Director, Freddy Ramirez, said.Fire Rescue personnel and others worked through the night in hopes of finding survivors.

State senator, Jason Pizzo, of Miami Beach, told the Miami Herald he watched as tactical teams of six worked early on Friday to sift through the debris. He said he saw one body taken in a yellow body bag and another that was marked. They were taken to a homicide unit tent that was set up along the beach.

Many people remained at the reunification centre set up near the collapse site, awaiting results of DNA swabs that could help identify victims.

Officials said no cause for the collapse has been determined.

Video of the collapse showed the centre of the building appearing to tumble down first and a section nearest to the ocean teetering and coming down seconds later, as a huge dust cloud swallowed the neighbourhood.

About half the building’s roughly 130 apartments were affected, and rescuers pulled at least 35 people from the wreckage in the first hours after the collapse.

Television video early on Friday showed crews still fighting flare-ups of fires on the rubble piles. Intermittent rain over South Florida is also hampering the search.

Raide Jadallah, an assistant Miami-Dade County fire chief, said that while listening devices placed on and in the wreckage had picked up no voices, they had detected possible banging noises, giving rescuers hope some are alive.

Rescuers were tunnelling into the wreckage from below, going through the building’s underground parking garage.

Personal belongings were evidence of shattered lives amid the wreckage of the Champlain, which was built in 1981 in Surfside, a small suburb north of Miami Beach.

A children’s bunk bed perched precariously on a top floor, bent but intact and apparently inches from falling into the rubble. A comforter lay on the edge of a lower floor. Televisions. Computers. Chairs.

Argentines Dr Andres Galfrascoli, his husband, Fabian Nunez, and their six-year-old daughter, Sofia, had spent Wednesday night there at an apartment belonging to a friend, Nicolas Fernandez.

Galfrascoli, a Buenos Aires plastic surgeon, and Nunez, a theatre producer and accountant, had come to Florida to get away from a Covid-19 resurgence in Argentina and its strict lockdowns. They had worked hard to adopt Sofia, Fernandez said.

“Of all days, they chose the worst to stay there,” Fernandez said. “I hope it’s not the case, but if they die like this, that would be so unfair.”

They were not the only South Americans missing. Foreign ministries and consulates of four countries said 22 nationals were missing in the collapse: nine from Argentina, six from Paraguay, four from Venezuela and three from Uruguay.

The Paraguayans included Sophia Lopez Moreira — the sister of first lady Silvana Abdo and sister-in-law of the president, Mario Abdo Benítez, — and her family.

Israeli media said the country’s consul general in Miami, Maor Elbaz, believes that 20 citizens of that country are missing.

Also missing was Arnie Notkin, a retired Miami-area elementary school physical education teacher, and his wife, Myriam. They lived on the third floor.

“Everyone’s been posting, ‘Oh my God, he was my coach,'” said Fortuna Smukler, a friend who turned to Facebook in hopes of finding someone who would report them safe.

“They were also such happy, joyful people. He always had a story to tell, and she always spoke so kindly of my mother,” Smukler said.

“Originally there were rumours that he had been found, but it was a case of mistaken identity. It would be a miracle if they’re found alive.”