Not sure whether anyone's said this already in this thread, but I know some people who live in earthquake zones stash their supplies in different locations. If a building collapses and destroys a part of your supplies or makes them inaccessible, you still have the other parts. That is, if you survive...
Definitely a good idea. In addition, our cars, it happens, are parked in the open. I make sure that there is a certain amount of minimum gear in each vehicle, fairly likely to still be accessible after an EQ and useful if we should decide to leave.