I've worked IT contingency planning for over a decade... I would not design a 30 billion dollar IT company with one datacenter in California for exactly this reason. Auto/factories are a much different thing... odds of single known asteroids hitting earth are about 1/250k in decades... odds of major earthquake in CA...
"The California Office of Emergency Services told KEYT.com that this equates to about a 1 percent increase in the likelihood of a major earthquake along the fault line through Tuesday." -- 1/100.