Interesting, thanks for posting.
Many fingers will be pointing. As a civil PE that has been though failure analyses on the owner's rep side, I'm guessing there will never be agreement on what caused the event, but people will latch onto something, usually from their perspective, and there are many.
In this case, immediate public safety is involved - my guess is these composite beams will not be used for such a span length anytime soon,. Iff they are used at all. their transportation and installation will be highly scrutinized.