A magnitude 5.2 earthquake occurred three miles south of Julian at 10:08 a.m. Monday, shaking much of Southern California, according to the U.S. Geological Survey.
The temblor started 8.3 miles deep, south of the Elsinore fault zone, one of the busiest seismic zones in California, according to the USGS. The earthquake is likely to be followed by many smaller aftershocks.
Scientists say the Elsinore fault is capable of producing quakes in the range of magnitude 6.5 to 7.5.
The San Diego Museum of Fine Art in Balboa Park briefly closed so that it could do a damage and safety check. It has since reopened.
The quake also produced shaking that was strong enough to be noticed on the 14th floor of the federal courthouse in San Diego.
This is a breaking news story and will be updated.