It's not that big of a risk, actually. The last time someone in California was killed by an earthquake was 23 years ago.
Where does it stop? Colorado was hit with the most powerful hail storm in it's history (I'll grant you, no one was killed, thankfully). It was the most expensive on record. There's a huge shopping mall that will be closed until November, it will take that long to fix the roof and flood damage. Point there is that the technology exists to mitigate a hailstorm in the upper atmosphere before it starts, but the question is who will pay for it?
As far as early warning systems go, what good are those? New Orleans had plenty of warning that Katrina was coming, yet thousands died. Every year tornado sirens go off and people still ignore them. Californians are so lackadaisical that they'll ignore any kind of early warning system.
