I note that the news reports are saying that there are over 670 bridges in the US with this "under-deck truss system". Their implication is that someone should demand that they all be closed for inspection because it may be a flawed design. My reaction is that this appears to be the only one of 670 to fail this way, so don't assume that design is the problem. Inspect, by all means (Ohio does so annually), but don't reach conclusions before you have the data.