San Francisco Earthquake

In the latest of 1906 earthquake anniversary activities, the USGS provides a Google-Earth based virtual tour of the 1906 San Francisco Earthquake. The 100th anniversary of the quake is April 18. About.com's 20th Century History Guide provides an overview of the earthquake along with an extensive gallery of historic earthquake photos. About.com's Geology Guide provides a collection of photos of landmarks that survived the quake.