The death toll climbed to 28 on July 5 in the collapse of a condo tower in the US state of Florida, where search work resumed after the dangerously unstable remaining portion of the building was brought down with explosives ahead of a coming tropical storm, officials said.

Some 117 people remained missing after the 12-storey Champlain Towers South crumbled over a week ago in Surfside, but an Israeli search official put the chances of finding survivors at “close to zero”.

Still, crews “were in full search and rescue mode” by early on July 5, hours after the remaining section of building was toppled in a haze of smoke and dust, Miami-Dade county mayor Daniella Levine Cava told a briefing.

At a later news conference she said one more body had been pulled from the rubble, raising the confirmed death toll to 28.

She said the demolition had gone according to plan and that searchers had found three more victims in the rubble after work resumed.

Levine Cava added that authorities had raised “millions of dollars, thanks to the generosity of people in this country and all around the world”, with funds to be distributed to impacted families.

Authorities had halted work at the site because the unstable structure posed a threat to search-and-rescue teams, especially ahead of the expected arrival of Tropical Storm Elsa, probably on July 6.

Experts are looking at possible pre-existing critical flaws in the building’s structure, and are surveying other older high-rises in the area for potential problems.