A controlled explosion has brought down the unstable remains of the collapsed apartment block in Florida, ahead of a threatening tropical storm, as rescuers prepare to resume searching for victims.
Key points:

  • Rescuers were hoping the controlled demolition would give them access to the garage area for the first time
  • There were also concerns that the rest of the building was a risk of falling
  • Those concerns have been exacerbated by Tropical Storm Elsa, which was a risk of bringing strong winds to the area

The precarious, still-standing portion of a collapsed structure was rigged with explosive charges and set for demolition, after suspending the search and rescue mission.
Video footage showed the 12-storey Champlain Towers South in Surfside, outside Miami, being demolished late Sunday local time, 10 days after most of the building collapsed.
A number of explosions could be heard and then the building started to fall, sending up massive plumes of dust into the air in the surrounding neighbourhoods.
More than 100 people are still missing after the Champlain Towers South condo building partially collapsed.(AP Photo: Wilfredo Lee
)
The decision to demolish the Surfside building came after concerns mounted that the damaged structure was at risk of falling, endangering the crews below and preventing them from operating in some areas.
Parts of the remaining building shifted on Thursday, prompting a 15-hour suspension in the work.
Approaching tropical storm Elsa added urgency to the demolition plans with forecasts suggesting there could be strong winds in the area.
The latest forecasts have moved the storm westward, mostly sparing South Florida, but National Hurricane Centre meteorologist Robert Molleda said the area could still feel effects.
Were expecting primarily tropical storm force gusts, Molleda said, referring to gusts above 64 kilometres per hour.
A 2018 engineering report found the apartment building had major structural damage before it partially collapsed.(AP: Matias J Ocner, Miami Herald
)
Rescuers hoping to access garage area for the first time
Through the night, rescuers were awaiting the “all clear” after the demolition so they could dive back into the task of trying to locate any survivors buried under the rubble.
Crews were to begin clearing some of the new debris so rescuers could start making their way into parts of the underground garage that are of particular interest.
Once there, they were hoping to get a clearer picture of voids that may exist in the rubble and could possibly harbour survivors.
More than 100 people are still missing after the Champlain Towers South condo building partially collapsed. (AP Photo/Mark Humphrey
)
Officials had previously said the search could resume from 15 minutes to an hour after the detonation.
“We are standing by. We are ready to go in, no matter the time of night,” Miami-Dade Mayor Daniella Levine Cava said.
“I truly believe that the family members recognise and appreciate that we are proceeding in the best possible fashion to allow us to do the search that we need to do,” she said.
Once a new pathway into the initial rubble was secure, we will go back to the debris pile, and well begin our search and rescue efforts, Miami-Dade Fire Chief Albert Cominsky said.
No-one had been rescued alive since the first hours after the June 24 collapse.
The confirmed death toll from the disaster is 24, with 121 people missing.
A makeshift memorial was set up near the site of the collapsed condominium for the victims.(AP: Jose A Iglesias, Miami Herald
)
Special demolition technique used
Residents in the area were told to stay inside until two hours after the blast to avoid dust raised by the explosion.
Local authorities had gone door to door to advise them of the timing and to ask them to keep windows closed.
The detonation aimed to bring the remaining portion of the building straight down and toward the street side, away from the existing pile of debris, said Miami-Dade Assistant Fire Chief Raide Jadallah.
This method was called “energetic felling”, which uses small detonation devices and relies on the force of gravity.
Search and rescue efforts continue as many celebrate the Independence Day national holiday in the United States. (Reuters: Marco Bello
)
Ms Levine Cava said it contained the collapse to the immediate surroundings to minimally disturb the existing mound of debris where scores of people were believed to be trapped.
Officials used tarps to visually mark the search area in case new debris scatters unexpectedly.
Ms Levine Cava acknowledged that the tragedy was continuing to unfold during an important national holiday.
“This July 4 we’re reminded that patriotism isn’t just about loyalty to country,” said Ms Levine Cava.
“It’s about loyalty to one another to our communities, to those in need whose names or stories we may not know ever, but to whom we are connected by compassion and by resilience.”
AFP/AP