[CurtEgerer]

I spent my early engineering career inspecting bridges. This should be fairly easy for engineers to figure out. From what I can see, the bridge looks to be a somewhat unusual truss design. Many, many bridges in the US are in very poor structural condition - if you crawled under some of these and looked around, you'd be shocked. I'll bet the Federal inspection reports over the years show some significant structural deterioration (i.e. corrosion, fatigue cracks, etc.). All it takes is a failure in one small section to bring the whole thing down with this sort of design. The current construction activity looks to be repaving only. If that's the case, the only potential problem would be unusual loading conditions. Were they stockpiling paving material on the bridge? Did they have heavy equipment concentrated in one area?