[RayChuang88]

If that's the case, NOW you wonder someone with structural engineering knowledge precisely placed a small bomb to detonate with very little sound but just enough force to cause a cascading structural failure.

[rxsid]

"If that's the case, NOW you wonder someone with structural engineering knowledge precisely placed a small bomb to detonate with very little sound but just enough force to cause a cascading structural failure."

Certainly not impossible, but IMV highly unlikely. This looks more and more like a tragic accident and is almost certainly a combination of structural/construction failures + land subsidence.