What faultline shifted during the san frasisco earth quake?

During the San Francisco earthquake of 1906, the major fault line that shifted was the San Andreas Fault. This event resulted in significant lateral displacement, with the ground on the western side of the fault moving northward relative to the eastern side. The earthquake caused widespread destruction and fires, leading to extensive damage in San Francisco and surrounding areas. The shift along the fault line was a key factor in the disaster's severity, illustrating the tectonic activity in California.