Man this is awful.
reminds me of this:
https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse
114 died with 216 due to structural issues. They actually they teach about this shit in most engineering classes as a case of someone making decision to change the design. Which MIGHT be the case it wasnt the engineers fault and it may the contractors fault. This is going to be a HUGE issue.
Especially when running construction projects if the contractors didnt follow design OR the may have possibly not been alerted to certain design changes etc.
It really either could be any phase of when they designed it, to when they got materials or if contractors didnt follow design, made shortcuts with materials etc.
This is so fucked up and its extremely sad people still dont learn from that tragedy I mentioned above. It was the worst accident in the US until 9/11 happened but I dont think many people know about it.
I work in this industry, but from a technical perspective and I wholly wonder if they had some system in place to track who did what because if not. Man all parties maybe fucked and for good measure for how this was constructed.