A beachfront condo building partially collapsed on Thursday killing at least three and injuring 12 others as 99 people are missing.

A wing of the 12-story The Champlain Towers South condominium in the community of Surfside came crashing down thundering at around 1.30 pm.

The tower resembled an invisible work of hacking off that ended in a gaping hole with the rest of the building standing as petrified witnesses.

As nearly 100 people are trapped inside, escalating fears that the death toll could climb sharply since the authorities are uncertain about how many people were in the building when it collapsed.

“The building is literally pancaked,” Surfside Mayor Charles Burkett said. “That is heartbreaking because it doesn’t mean, to me, that we are going to be as successful as we wanted to be in finding people alive.”

Hours after the collapse, rescuers were trying to reach a trapped child whose parents were believed to be dead. In another case, rescuers saved a mother and child, but the woman’s leg had to be amputated to remove her from the rubble, Frank Rollason, director of Miami-Dade emergency management, said.

Gov. Ron DeSantis, who toured the scene, said television did not capture the scale of what happened.

Rescue crews are “doing everything they can to save lives. That is ongoing, and they’re not going to rest,” he said.

Teams of 10 to 12 rescuers at a time entered the rubble with dogs and other equipment, working until they grew tired from the heavy lifting, then making way for a new team, said Florida Chief Financial Officer Jimmy Patronis, the state’s fire marshal.

“They’re not going to stop just because of nightfall,” Patronis told Miami television station WPLG. “They just may have a different path they pursue.”

President Joe Biden promised to provide federal aid if requested.

Hotels opened to some displaced residents, the mayor said, and deliveries of food, medicine and more were being hastily arranged.

About half of the building’s roughly 130 units were affected, the mayor told a news conference. Rescuers pulled at least 35 people from the rubble by mid-morning, and heavy equipment was being brought in to help stabilize the structure to provide more access, Raide Jadallah of Miami-Dade Fire and Rescue said.

A total of 22 South Americans were missing in the collapse — nine from Argentina, six from Paraguay, four from Venezuela and three from Uruguay, according to officials in those countries.

Barry Cohen, 63, said he and his wife were asleep in the building when he first heard what he thought was a crack of thunder. The couple went onto their balcony, then opened the door to the building’s hallway to find “a pile of rubble and dust and smoke billowing around.”

“I couldn’t walk out past my doorway,” said Cohen, the former vice mayor of Surfside.

Surfside City Commissioner Eliana Salzhauer told WPLG that the building’s county-mandated 40-year recertification process was ongoing. Salzhauer said the process was believed to be proceeding without difficulty. A building inspector was on-site Wednesday.

“I want to know why this happened,” Salzhauer said. “That’s really the only question. … And can it happen again? Are any other of our buildings in town in jeopardy?”

The seaside condo development was built in 1981. It had a few two-bedroom units on the market, with asking prices of $600,000 to $700,000. The area’s neighborhood feel offers a stark contrast to the glitz and bustle of nearby South Beach.