The mission to rescue possible survivors from the rubble of a collapsed U.S. condo building has entered the sixth day. But experts said it could take years before the cause of the collapse becomes clear.
As of Tuesday evening, at least 12 people have died and 149 others remain unaccounted for after a 12-story residential condo building collapsed in the southern U.S. state of Florida, according to officials.
Authorities are engaged in a major search and rescue operation, which entered the sixth day on Tuesday, as teams of rescuers carefully sifted through the pile of debris in a bid to locate survivors.
The collapse occurred around 1:15 a.m. (about 0530 GMT) on June 24 at the Champlain Towers South condominium in Surfside -- a small beachside town that sits around 9.6 km north of Miami Beach.
"Nobody is giving up hope here. Nobody is stopping," Surfside Mayor Charles Burkett said Tuesday at a press conference. "We are dedicated to getting everyone out of that pile of rubble."
SEARCH GOING SLOWLY
The search is going slowly, and some families of missing persons have expressed their frustration to U.S. media.
Miami-Dade Fire Rescue Chief Alan Cominsky said the process was "methodical" and "strategic." Rescue operations include the use of thermal imaging, sonar, rescue dogs and individuals.
"A search with this type of collapse is extremely difficult," Cominsky said at a press briefing on Friday. "As this equipment comes in, we will use it to assist to move certain pieces of debris. We can't just move it all at one time. It has to be a very slow process."
CAUSE OF COLLAPSE UNCLEAR
Experts said figuring out what caused the collapse will take years, not just days, weeks or months.
Engineers and researchers nationwide are scratching their heads, trying to make sense of the early morning collapse, as well as whether other structures in the state and even nationwide might be in danger of a similar disaster.
Some experts have speculated whether a rise in sea level has led to increasing corrosion from saltwater during tides. The sea level in the town has risen up to 8 inches (about 20.32 cm) over the past four decades due to climate change, according to Brian McNoldy, a climate and weather researcher at the University of Miami, CNN reported.
Other experts speculated about how solid and stable the ground underneath the building might have been, or whether construction standards were up to par.
"If a lot of things were breaking lower down, you would have seen the dust below," Michael Chajes, a professor of civil and environmental engineering at the University of Delaware, was quoted as saying by USA Today.
According to Allyn Kilsheimer, the chairman of the board of DC-firm KCE Structural Engineers, there are as many as 30 theories on what could have caused the condo to collapse.
