above is the far side, and what it had looked like, notice the top half, which I will guess is the hip high wall to keep vehicles from driving off the bridge sideways... a K Rail is one term for it, Jersey Barrier is another
here you can make your own estimation how much of the bridge tumbled over onto the truck below, at 9.8 meters per second squared... about 1.5 seconds from the instant it parted ways with the bridge to crushing the passenger compartment of the truck.
http://www.dailymail.co.uk/news/article-3037982/Young-couple-baby-son-killed-chunk-CONCRETE-falls-Washington-state-bridge-crushes-pickup-truck.html
Daniel, an construction inspector (who knew one was reading myblog ?!?! ) offered his experience to comment:
I have to disagree with your headline implying that accident was due to structural deficiency.
This looks like it happened during construction of a new sidewalk which was on top of the overhang, adding 532lb +/- per linear ft of bridge (assuming 6' wide & 8" deep).
The contractor had kick braces and overhang forms in place, which is practice for placing fresh concrete.
It also looks like there is a saw cut down the edge of the deck along out side beam and no exposed reinforcement.
My guess is that the contractor expected the kick braces to hold everything up until the could complete the saw cut and crane lift the deck portion and Jersey barrier off the side in a couple of lifts.
To me -this looks like contractor negligence not a rotten bridge. The quoted sufficiency rating of 95.3 is a measure of how well the bridge services the road way, items such as alignment, no of lanes and clearance. The Structural Rating is the number everyone should be concerned about, rating of deterioration of structural members, deck, impact damage and erosion.
I do agree that our highway infrastucture needs a massive amount of attention but that is not what is at fault in this case.
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