You've already named two potential companies that could be attributed unfair amounts of blame. Beyond them, there are a large number of potential officials tha

You've already named two potential companies that could be attributed unfair amounts of blame. Beyond them, there are a large number of potential officials that could have leaned on / been leaned on or through nepotism or laziness been a part (or not part) of the planning, design, implementation etc of the bridge that are partly or largely responsible for design/funding choices to this bridge. There are countless examples of people receiving undue flak before being conclusively proven as guilt free, it is often prudent to wait before leveling accusations - that is what the NTSB does in it's processes - often to a fault. I think it is unnecessary snark to ask me if the bridge collapsed, please don't be crude.