06/21/2006: Apparently, the southern San Andreas Fault is cocked and locked. The last big quake from that fault–in 1690–was about 7.7 on the Richter Scale.
Anything 7 or higher would be very severe, as this would effectively be a direct hit on Los Angeles.
Anything 8 or higher would inflict damage as bad as–or worse than–Katrina.
The Northridge quake of 1994, which measured 6.7, killed 56 people, knocked down NINE bridges on three different freeways, and was–at the time–the costliest natural disaster in American history.
Good thing that one struck at 4:30 in the morning.