The 1906 earthquake in San Francisco was one of the most important earthquakes. It was confusing for geologists because of its great rupture length. The significance of the fault would not be fully appreciated until the discovery of plate tectonics more than half a century later. It helped us to better understand the scientific perspective of earthquakes.
The earthquake was felt from southern Oregon to south of Los Angeles and inland as far as central Nevada . At 5:12 a.m., Pacific Time, a foreshock occurred with enough force to be felt widely throughout the San Francisco Bay area. The great earthquake broke loose some 20 to 25 seconds later its epicenter was near San Francisco . Violent shocks blasted through the strong shaking which lasted some 45 to 60 seconds.
Every major Earthquake has to be documented and a full report has to be written, documenting fatalities, damage, and injuries. This is necessary because it can help us learn how to predict earthquakes. The Lawson report was the report written for. It is the basic reference about the earthquake and the damage it caused, geologic observations of the fault rupture and shaking effects, and other consequences of the earthquake.
The people who experienced the earthquake remembered the earthquake the most for the fire it spawned in San Francisco. Shaking damage, however, was equally severe in many other places along the fault rupture. At the time it was believed that there were 700 deaths caused by the earthquake and fire, but it is now believed that that was an understatement of the total casualties by a factor of 3 or 4. Most of the fatalities occurred in San Francisco , and 189 were reported elsewhere.