The San Francisco Bay Area was rattled early this morning by a magnitude 4.3 earthquake along the Hayward fault lineSleeping residents of California’s San Francisco Bay Area were rattled awake by a magnitude 4.3 earthquake in the early morning hours of September 22. The epicenter of the earthquake was about 4.7 miles deep, according to a preliminary report from the U.S. Geological Survey. Amanda MontañezThe earthquake occurred near the Hayward fault line, which runs from the north side of San Francisco Bay to southeast of San Jose. The largest known earthquake on record in the area of this fault was a magnitude 6.8 event in 1868. By comparison, San Francisco’s deadly 1906 earthquake, which occurred along the San Andreas fault, was at least a magnitude 7.7 event.