In the coming decades, a magnitude 7.1 or 7.3 earthquake - similar to the deadly quake that rattled central Mexico last year  - would almost certainly strike a densely populated part of the state (the San Andreas fault runs through most of California, as the map below shows), potentially leading to tens if not hundreds of thousands of casualties. The local economy would lie in ruins and it would take years to for the area to recover.

With this in mind, it's perhaps no surprise that government agencies, businesses and other organizations in Arizona have recognized the need to prepare. To wit, the Associated Press reports that local organizations are participate in an exercise to practice how the state would respond to a migration of 400,000 people after a catastrophic earthquake in Southern California.