Southern California was shaken Friday by an earthquake with a preliminary magnitude of 4.1. The epicenter was recorded about a mile northwest of Lytle Creek in the mountains east of Los Angeles, according to the U.S. Geological Survey.
A magnitude-10 earthquake had occurred in the area in the past 3 days, according to the Los Angeles Times, which says there are an average of 25 magnitude-4 to 5 quakes in California and Nevada each year, based on a sample from the past three years.