[elorant]

If Google App Engine goes down many sites will stop working. OAuth services will also start to fail. So will custom search provided to 3rd party sites (ok that may not sound too bad but you never now). Then there is cloud storage which in many cases is used as a backup mechanism. And how about the gazillion of sites that load js libraries from Google's CDN? Sure, a day or two is bearable, but make it a week and then the shit hits the fan.

The one thing you should bear in mind about earthquakes is that in many cases the aftershocks make more damage than the main one, because damage accumulates. Which means that critical infrastructure could take weeks to become fully operational.