If you watch lots of disaster documentaries, you'll realize that "warnings went unheeded" or even "problems were explicitly acknowledged in formal reports over several years but not actually resolved" are incredibly common fact patterns in structure collapse.

Usually structures will give some signs of impending failure, but also repair or remediation is usually very expensive and disruptive, and there are thousands of crumbling structures that require it. Only in retrospect is it obvious where we should have concentrated our limited resources.