Rather than mimic 3 spans of different heights, they could have done something like a trapezoid that wouldn't buckle.
I suspect this is the problem with engineers' perception of structural FEA. There was a pretty high profile (as in billions lost) similar case in Boeing 787 program.
And I am afraid even to think of how many things end up deep into their safety margins in similar scenarios.
Engineers are responsible for structural feasibility. The structural engineers should have been the ones to decide design.
Well, the buck (I mean DA) stops at PE stamp on the design. Those working for the firm without PE doing actual FEA and design also didn't do well.
Overall, I am not going to apportion the responsibility - there is always many things to consider and multiple people to blame. But I hope you're not going to deny responsibility of design team?
You are missing the fact that the design is done by engineers.
Talking about engineers... there had been a great tradition of an engineer standing under the newly built bridge...