(CNN)The collapse of a high-rise condo tower in South Florida early Thursday morning has left at least four people dead and 159 more currently unaccounted for. Now, as the search for survivors continues, a critical question looms: What caused the building to fall?

Officials are promising an urgent inquiry as engineers have said it is impossible, at this stage, to pinpoint a precise reason. Local officials familiar with the condo complex, which is only four decades old, have repeatedly shot down rumors that it was in any unusual state of disrepair.

An attorney for the building's condominium association, Kenneth Direktor, warned against early speculation. The building, he told CNN, had been subject to a series of inspections "over the last several months" as part of its milestone 40-year safety certification process.

"Nothing like this was foreseeable," Direktor said. "At least it wasn't seen by the engineers who were looking at the building from a structural perspective."

The only repairs that recently took place, he added, were work on the roof.

At a press conference on Thursday, Surfside, Florida, Mayor Charles W. Burkett dismissed the suggestion that the rooftop repairs should have been a red flag. (It is unclear if the engineer's inspection process located any other concerns or recommended any other work).


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