Bad deal...

[OntarioHunter]

I'm not suggesting it was planned as some here are assuming. Just seems weird that the entire bridge would go down. I would have assumed a bridge that big in that busy of a port would have been designed with a potential collision in mind. Most things are built for worst case scenario. Especially fed and gov things like this. At least around here they are.

The box girders (trusses) are all hooked together. When one goes, it pulls down the next which pulls down the next. Suspension bridges provide better insurance against this sort of chain reaction collapse simply because they typically have few piers to knock out. The problem with them is they require significant anchoring at the ends. This is not always environmentally possible. Sometimes the geography just isn't there. I suspect that may be the case in Baltimore. It's why the Hughey Long Bridge in New Orleans is also piers and girders. Bed rock is WAY down under the surface. I was told when working as a NPS ranger there many years ago that the Hughey Long Bridge piers sit on foundations of ... cotton bales in vaults under the river! Also girder and pier bridges are cheaper to build. It will be interesting to see what technology is used to replace the Key Bridge.