On April 18, 1906, a devastating earthquake resulted from the rupture of over 270 miles of the San Andreas Fault, from San Juan Bautista to Eureka, centered immediately offshore of San Francisco. The quake is estimated by the USGS to have had a magnitude of 7.8 on the Richter scale. Water mains ruptured throughout San Francisco, and the fires that followed burned out of control for days, destroying approximately 80% of the city, including almost all of the downtown core. Many residents were trapped between the water on three sides and the approaching fire, and a mass evacuation across the Bay saved thousands. Refugee camps were also set up in Golden Gate Park, Ocean Beach, and other undeveloped sections of the city. The official death toll at the time was 478, although it was officially revised in 2005 to 3,000+. The initial low death toll was concocted by civic, state, and federal officials who felt that reporting the actual numbers would hurt rebuilding and redevelopment efforts, as well as city and national morale. The death toll from this event had the highest number of deaths from a natural disaster in California history.