San Francisco Earthquake; April 18, 1906 Magnitude 7.8 Striking early in the morning, the “Great Quake” of 1906 left more than 80 percent of the city damaged from the quake itself and from fires. With the quake’s epicenter near San Francisco, tremors from the shaking caused by rupture and horizontal displacement of the San Andreas fault were felt from southern Oregon to southern California and inland to central Nevada. Although some estimates place the number of deaths from the earthquake and fires at around 700, the number is now thought to be at least 3,000. The 1906 earthquake remains one of the most significant earthquakes in U.S. history. Scientists study the quake as an example of seismic cycles in the Bay Area in which a huge quake, of magnitude 7.0 or more, is preceded by a series of smaller earthquakes.