What I consider the biggest obstacle to hiking home is having to cross the "Ship Canal", which is a canal for shipping which links Lake Washington to the ocean.
The George Washington Memorial Bridge probably wouldn't survive a major earthquake as it looks to be of a similar design to the one that fell down a few years back in Minneapolis. The Fremont Bridge looks to be a better bet and you should have somewhere to
sit whilst you ponder how to make the crossing unless of course the Tsunami has swept it away.
Looking at the distance the swim would take to cross the canal from Google Maps looks to be about 50-60 metres so looks quite doable.