Your comment is both incorrect and childish and this is actually an important and interesting topic, please don't participate on HN discussions with comments like this.
If you want to look at devastating datacenter loss, if anything happened to Northern NJ the markets would go into a tailspin.
I'm just tired of the obviously incorrect proposition that Bay Area is producing just frivolous photo sharing and social communication tools (which both has a huge value for humanity, but that's a different story) and I seriously find it an interesting thought experiment what would happen on a global scale if the Bay Area would be devastated by a big earthquake.
The obvious tech giants like Google, Apple, Oracle and Cisco are arguably supporting a huge number of businesses and organizations around the world. But a glance through a list of just publicly traded US SaaS companies reveals that about 40% are from the Bay Area. These offer SaaS-based solutions ranging from HR tools (Workday), IT service monitoring (Splunk), ITMS (ServiceNow), CRMs (SalesForce), ERPs (NetSuite), Insurance backends (Guidewire) to supply chain management (e2open), to just name a few.
If Bay Area suffered anything resembling 2008 Sichuan earthquake, it would halt a good part of the economy for a while.