Wolfepack, that's a good list. I would only change two things.
Extra socks. Your feet are your lifeline in that situation.
All that info on your USB, couldn't that be a nice gift if someone robbed you? SS and account numbers...
The bridge will be up or it will be down. Seattle sits on eight faults, and each one could probably give different results. A tidal wave could skew even that.
One thing that comes to mind is that some of the people you work with might be traveling in the same direction, a possible asset. Does anyone have a boat moored nearby?
Does your company have any plans in place for a disaster like that? Maybe you could start something. It might be nice to get people accustomed to the idea that they might be taking in coworkers for a few days -- maybe you.
Lono is right, it could be hard to walk away from the people you work with. And if the bridge is down, you might be forced to hang around.
I have a similar, but worse, problem. I drive to Seattle almost daily, but live 85 bird miles south. At least two rivers to cross, if I made it out of Seattle. On foot, almost certainly. Blech!
Sue