Interestingly, there's a claim that it's "an engineering failure," if it was really that bad, then they were lucky that it collapsed before the building was built over it. Otherwise, a death toll in the hundreds might have been the case.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!
It's hard to know what the "engineering failure" was, but I hope they find out and change their practices.
It could be a failure of temporary bracing for construction, while the finished building might have been okay. This was the case for a Canadian bridge that collapsed during construction, where temporary bracing was found to have been inadequate, but the final bridge would have been okay: 2nd Narrows Bridge Collapse