The administration of Los Angeles is preparing for a "nuclear event" which would destroy much of the area and kill countless victims. It is under the assumption that a 10 kiloton nuclear device will detonate in downtown LA.
The idea is that either North Korea or Iran will be able to send a missile to the West Coast, or a terrorist cell will plant such a device in the city. Either way, not a pretty picture.
Could this be why there are so many secret military operations going on in San Diego??