Now, there is even more reason to worry.
The dollar figure is $210 billion. That's much higher than the $125 billion in damage caused by Katrina.
Even worse, only about 7 or 8 percent of the economic losses caused by an earthquake on the Hayward fault, which would be focused along the East Bay's urban core, would be covered by insurance, according to Mary Lou Zoback of Risk Management Solutions.
"We're talking about huge potential losses to private businesses and homes and we're not even including public buildings and infrastructure," Zoback said.
Seismologist Brad Aargaard Aargaard said news simulations, which incorporate dozens of scenarios, could show city planners and emergency managers the various patterns of shaking for which they need to prepare.
The magnitude of earthquake and where the rupture starts have a strong influence on the impact of a quake, he said.
Zoback said that although the predictions about the likelihood of a large earthquake are scary, the good news is that the Bay Area is better prepared to deal with one that most regions are.