What in the world does that mean?
It is apparently a bureaucratic designation reflecting the general/categorical condition of a particular bridge, according to its age, type and observed manifestations of aging/weathering/usage, etc. It seems to be used to place a bridge on a given schedule of testing and observation. It does not seem to be, by itself, a panic signal to be ignored or not.
I wish the media would begin to grow up about very basic differentiations in terminology. Many reporters confuse a bureaucratic label with some sort of normative statement, as in "the official was dangerously negligent." It doesn't seem that officials of any sort did anything different with the fallen bridge than they do with any other of the thousands of bridge in the same designation: watch carefully, accelerate the monitoring/testing schedule according to the engineering norms that are currently accepted. It may be that these criteria need to be looked at and updated according to what is learned from the collapse in Minneapolis. But that may not be the need--we just don't know. No one has categorically eliminated any possibilities yet, from acts of nature to problems with the ongoing construction to criminal activity.
In case no one's noticed, there are still operations in progress to recover the bodies of victims.