Magnitude 4.1 Earthquake Shakes Southern California

Much of Southern California got rattled late Friday morning, thanks to a 4.1 magnitude earthquake, reports KTLA. The quake struck at 10:55am Pacific time north of Rancho Cucamonga in the San Gabriel Mountains, according to the US Geological Survey. No immediate reports of injuries or damage were reported, notes the AP. "The Los Angeles Fire Department remains in a normal operating mode," the department tweeted. "There have been NO reports of injury, structure or infrastructure damage within our ... jurisdiction."

It's likely that residents in Los Angeles, Riverside, San Bernardino, and Orange and San Diego counties felt the shaking, according to a USGS map of shock waves. For context, a story in the Los Angeles Times notes that an average of 25 earthquakes a year with magnitudes between 4 and 5 hit California and Nevada. Of note: The Times story was authored by "Quakebot," run by the USGS, though the LAT says an editor reviewed it before publication. (More earthquake stories.)