Wow, the third picture in the photo gallery says it all.
"Some of these components were made of cast iron, a brittle material and unsuited to this particular purpose."
Of the theories of collapse, the second seems most plausible. The bridge seems too close to the water to have been caught up in Tacoma-like crosswinds, which also makes #3 somewhat sketchy in my mind. The stress and sheer in those pictures seems like it would have had to be impact related - but then again, if unsuitable materials were used, wind sheer would not have had to be particularly strong to tear down sections. So, I guess I don't really know.
Interesting article though. I may see about finding one of the books on the suggested reading list.
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Just like regular Elvis...only smaller.
You'll find a whole heap of info' if you 'Google' it. The museum in Dundee has a lot of recovered personal belongings (letters, postcards, etc) It's pretty poignant.
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There's no such thing as bad weather....only the wrong clothes!