7 dead as of this morning's report...more casualties expected and people are still missing.

I still have to ask. How? Bridges simply do not just collapse like this. This one pancaked down, indicating structural weakness or damage on both ends that caused a simultaneous structure failure, allowing it to fall. That doesn't just 'happen.' I'm saying it may not have been terrorism, but I have my doubts that it was an accident.

sounds like it was just the nature of the bridge, since they where saying it was 40+ yrs. My thoughts and prayers go out to the family's.

I see there are 2 bridges there. Is that the main bridge or is just the othe side of I-35W? only been up that way once awhile back.

That's the main 35W Bridge. There are quite a few bridges crossing the Mississippi in the Cities.

Not old at all...the Brooklyn Bridge is approaching 100 years old. The Golden Gate Bridge in the San Francisco Bay was built in the 1930's during the great depression. Those are just a few examples. Of course, those bridges and others like them have full time dedicated maintenance crews. Those bridges are constantly maintained and therefore are in better shape than some "newer" bridges. I used to be a bridge inspector and something that could cuase a structural collapse of that magnitude would be so blatantly obvious to the naked eye it couldn't be ignored. Now if it's scour, that is a totally different issuse altogether. I don't think we've ever seen a disaster of this magnitude before that was not due to the fault of a pilot or ship. The Tacomos Narrows bridge comes to mind but that was decades ago and every one got off of it. It fell apart slowly. The inspectors and engineers have a long, arduous time ahead of them to piece this complex puzzle back together. Right now we only can speculate, and speculation will get us nowhere.

Correction, the Brooklyn Bridge was completed in 1883...that makes it over 120 years old.

Scour is the process by which water begins to erode away the riverbed at the foundation of the piers (the piers are the vertical supports that go from the water up to the bridge). Overtime, the force of the water can erode away enough material that the foundation weakens and becomes lose, if you will. Worst case secenario is that the piers topple over, of course causing the supported structure to collapse. Scouring is a very slow process and is much more difficult to assess and keep track of because since the foundation is under water, in most cases one must ucs a SCUBA diver to check it out. Scour is not much of a problem in slow-flowing streams but tends to occur in steams where the water moves very rapidly and with great force. Given that the Mississippi flows very gently I doubt scour is the culprit in this case. But only time will tell.

I'm not a structural engineer, obviously, but what I think when they find the cause it will be because of a stress fracture that finally couldnt take the weight load, plus the fact it's one of those 2 column supports. They did this because of barge traffic
This particular bridge you see in photos or on tv don't really show how big this bridge is.