Investigators are trying to verify loads and stresses on these plates at specific locations as well as the materials used to construct them.
Officials stressed the finding is preliminary and would not say exactly where the plates were located or whether failure would have caused the collapse.
Here is a picture I found on Flickr showing the collapse from ground level...in the left hand side of the frame you can see one of the "gusset plates." Notice how it crumpled just a bit. I don't think this particular plate caused the collapse. Most that I've seen in pictures seemed to have held up just fine...but the ones that failed are probably burried under all that concrete roadway.
