of microelectronics fabrication plants could have an economic effect extending worldwide. The current estimates of the probability of a major earthquake on any of the numerous regional faults range up to 70 percent within the thirty-year period 2000–2029. A recent quiet period following many years of minor activity is considered to be particularly ominous by many, although geologists have not yet been able to predict earthquakes with any useful accuracy. They do warn that all residents of the region should be prepared for a large event and its subsequent effects (e. g., lack of water, firefighting, first aid, electricity, motor and heating fuels, etc.) and that much life-safety protective work remains to be done. Retrofits for survivability It is primarily the likelihood of a severe earthquake on the Hayward or San Andreas faults that has spurred a substantial effort to retrofit and sometimes replace large structures at risk, particularly the eastern and western spans of the San Francisco–Oakland Bay Bridge, the San Francisco and Oakland city halls, and numerous elevated rail, road, and pedestrian structures and overpasses. Much work remains to be done in the region and progress is being hampered by budget constraints imposed by trickle down federal-state-regional deficits, design and construction delays due to state and local political bickering over design, and unexpectedly high steel and cement costs due to the extensive construction work being done in China. Nonetheless, Bay area cities and counties have long expected a major earthquake and as a result all building in the past 30 years has been required to adhere to strict guidelines regarding earthquake resistance. Of all the earthquake prone regions of the world, the San Francisco Bay Area is among the most prepared structurally for the eventuality of a major quake while remaining grossly unprepared in both civil response planning and in the retrofitting of older buildings. Further information Virtual tour The Google Earth website, in cooperation with the United States Geological Survey, has prepared a virtual helicopter tour of the fault, with much additional information available through the tour. Potentially dangerous landslide areas are also marked, showing great areas beyond the fault that could be rendered uninhabitable by a major event. Special exhibit Fremont Earthquake Exhibit: The Hayward Fault ExposedThis geotourism exhibit (April through October 2006, now closed) featured a 12- to deep pit exposing the Hayward Fault, which could be viewed "face to face" from a shaded platform