When I 1st saw this last nite, and even heard 1st thing mention of terrorism, I dismissed that theory.
These nutcases aren’t going to bother with a little bridge in the middle of the country when they haven’t brought down all the “important” places in the US. This would be like 10th-tier target.
Unless it was just some local Moslem Somalis on their own mission.
It would have to be explosives and it would be instantly detectable. Bring in independent explosives experts and let them look.
Then there will never be any valid questions about this.
Even this doesn't wash out. Just placing explosives haphazardly would not bring down the bridge, someone would need to know exactly where and how to place them. An amateur would have probably put them on the piles and from everything I've seen the piles were intact.
Anyone with the means and ability to do this would have gone after a much more high profile target.
This WAS NOT terrorism.