A preliminary 3.5-magnitude earthquake struck Southern California near Ontario on Saturday morning at 10:05 a.m., with the epicenter located about three miles southeast of the city. The quake was followed by a 3.9-magnitude aftershock 30 minutes later. Residents in nearby areas such as Corona and Fontana reported feeling the tremors, but there were no immediate reports of injuries or structural damage. Earthquakes of this magnitude are relatively common in California, though they rarely cause significant damage. Authorities and news organizations have emphasized the importance of being prepared for larger quakes by having an earthquake kit and knowing safety procedures. This story is still developing, and updates may follow.