[spanalot]

http://www.nytimes.com/2007/08/06/us/06collapse.html?_r=1&oref=slogin

tons of construction materials stored on bridge

[XR7]

So far, investigators say they have ruled out nothing and will consider everything from the expansion and contraction of the bridge in the extreme weather conditions of Minneapolis to the possible corrosive role of bird droppings.

You gotta be kidding me!