My boss died in the Hyatt disaster which happened in KCMO in I think the early 80s. They found out that the bolts that held up the inside bridge were not well designed and the entire bridge fell killing hundreds of people.
Condolences to your former boss’ family.
It was a little more complicated than that. The contractor used the wrong grade of nuts and skimped on the washers as well, so the walkway was being held up by weaker nuts without the load being properly distributed through the beams by the correct washers.