Near the end of the NTSB's final report on the FIU bridge collapse, NTST Vice Chairman Bruce Landsberg compared the collapse to the Challenger Space Shuttle disaster. The scale and scope of each was large and red flags were raised prior to incidents but no one stopped the work or launch to prevent the tragedies from occurring. Individual organizations and team members knew circumstances weren't right but let other people in the chain or command lead. In these cases, and others, often people with the most knowledge about the issue are unsure or not confident that their specialty within the project is a major issue. Sometimes, project leaders who are responsible for the overall project are not knowledgeable enough at each specialty to know when items are work stop issues. With varying personalities, time and budget crunches, perceived roles and more, making key stand down decisions can be very difficult. The right perspective and decision after an incident is also easy to have.
In safety and work planning 101, most contractors are taught that safety and quality incidents occur at higher rates when scopes change. The NTSB identified the work to re-tension the structure as a cause of the collapse and change order or change in scope. It's easy to look back and say a revised work plan should be developed for this change now that something bad has happened but unfortunately it proves the accuracy of contractor training in regards to changes. Though not engineers capable of fully identifying the structural stability of the bridge before, during and after the re-tensioning, work planning might have identified that the road should be closed for the work. While this wouldn't have prevented the collapse and maybe injuring workers, it would have kept the public out of harm's way. Again, it's easy to point out how to do things better after the fact and outside the urgency of the repair. It does highlight the need for sound construction processes and the need to build according to sound practices every time.
Full NTSB report: https://www.enr.com/ext/resources/Issues/National_Issues/2019/11-Nov/18-Nov/NTSB-Final-FIU-Bridge-Collapse-Report.pdf
Focus Article on Vice Chair Statement - https://www.enr.com/articles/48117-ntsb-vice-chairman-slams-design-construction-team-for-miami-bridge-collapse
