The stillness of Southern California's early morning was broken by a magnitude-4.0 earthquake centered near Ontario, as reported in NBC Los Angeles. The tremor, which occurred at 3:51 a.m., was felt across various parts of the region, including Los Angeles, Whittier, Culver City, and others; it was accompanied by a magnitude-2.0 aftershock approximately half an hour later.
The earthquake's epicenter was located just south of Highway 60 near Ontario International Airport at a shallow depth of three miles; the shake was downgraded from an initial assessment of 4.3 to 4.0 magnitude and was followed by several minor aftershocks the strongest of which was a 2.5, according to details from KTLA 5 News, alarming residents with one viewer remarking "I'm in Eastvale and surprised it was only 4.1! It shook my house violently! It felt like a car had hit the side of my house," and another stating "In Fontana and felt it shook my door and thought someone was knocking on it till the entire house shook."
No significant damage or injuries were reported shortly after the quake, which acted as a sharp reminder of California's seismic activity; the state sees thousands of quakes each year, most of which register low magnitudes, as cited by KTLA 5 News. During such events, the importance of earthquake preparedness is underscored; the California Department of Public Health urges residents to follow the "Drop, Cover, and Hold On" protocol during seismic activity to minimize potential injuries.
The US Geological Survey's impact map reflected that the tremor was felt in various counties including Riverside, San Bernardino, Los Angeles, and Orange, and potentially as far south as northern San Diego County, this phenomenon highlights the reach of the quake beyond its epicenter, a preliminary 4.0-magnitude earthquake struck near Ontario this morning, shaking was reported in Los Angeles, Santa Monica, Torrance, Redondo Beach, and Culver City followed by a 2.5-magnitude aftershock at 4:04 a.m., also near Ontario, as detailed by CBS News Los Angeles.
