At the dawn of the 20th century San Francisco was the place to be; a hub of trade and travel business and banking. Located just to the east of the San Andreas Fault the bay area is interlaced with eight major earthquake-producing faults. We examine the cataclysmic earthquake that struck on April 18 1906-it jolted the city for 50 seconds the earth split for 270 miles and a resulting firestorm raged for three days. Amazing photographs document the city's destruction and efforts to rebuild. But the rush to get back in business came at a price-the city was rebuilt on the same seismic hazards. Now scientists warn that if it happens again damage and casualties will be much worse. The potential catastrophe unfolds through state-of-the-art graphics with bridges collapsing high-rise fires and freeways destroyed. A similar seismic jolt today would lead to a mega-disaster in San Francisco with billions of dollars in damage and casualties in the tens of thousands.