San Francisco Earthquake of 1906
At 5:12 a.m. on April 18, 1906, a magnitude 8.3 (Richter Scale) earthquake struck San Francisco.
With thousands of un-reinforced brick buildings and closely-spaced wooden Victorian dwellings, the city was poorly prepared for the quake. Collapsed buildings, broken chimneys, and a water shortage due to broken mains, led to several large fires that soon coalesced into a citywide holocaust. The fire raged for three days, sweeping over nearly a quarter of the city, including the entire downtown area.
The San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, CA and the coast of Northern California at 5:12 A.M. on Wednesday, April 18, 1906. The most widely-accepted estimate for the magnitude of the earthquake is a moment magnitude (Mw) of 7.8; however, other values have been proposed, from 7.7 to as high as 8.25. The main shock epicenter occurred offshore about 2 miles (3 km) from the city, near Mussel Rock. It ruptured along the San Andreas Fault both northward and southward for a total of 296 miles (477 km). Shaking was felt from Oregon to Los Angeles, and inland as far as central Nevada. The earthquake and resulting fire is remembered as one of the worst natural disasters in the history of the United States. The death toll from the earthquake and resulting fire, estimated to be above 3,000, is the greatest loss of life from a natural disaster in California's history. The economic impact has been compared with the more recent Hurricane Katrina.
Today In History: Earthquake!
Wikipedia: 1906 San Francisco Earthquake