A magnitude 4.2 earthquake shook a wide swath of Southern California on Wednesday night.
The earthquake, centered in San Bernardino, struck at 7:43 p.m. and resulted in light shaking across the Inland Empire, including in Riverside, Fontana, Rialto, Rancho Cucamonga, Moreno Valley and Redlands, according to the U.S. Geological Survey.
Light shaking is defined by the Modified Mercalli Intensity Scale as feeling like a heavy truck struck a building.
Colton got a shaking, at about a mile from the quake’s epicenter. Police, however, had not “received a single call” for aid as of about 9 p.m., Sgt. Mike Farcas told The Times. The San Bernardino County Sheriff’s Department and police in Rialto, located about two miles from the quake’s center, echoed that statement.
Weaker shaking was felt across the region, including in Los Angeles, Long Beach and Orange County. Residents said on social media shaking was felt in Ontario, Yorba Linda and downtown Los Angeles. A resident in Rowland Heights said she felt three seconds of shaking, as if she were on a boat with waves moving rapidly.
The epicenter was 1.5 miles southwest of downtown San Bernardino and half a mile north of the San Bernardino Depot train station. The quake began just east of the mapped traces of the San Jacinto fault, one of the region’s most active and potentially dangerous fault lines.
The San Jacinto fault spans about 130 miles and runs from the Cajon Pass in San Bernardino County southeast toward the Mexican border. The San Jacinto fault is one that worries earthquake scientists because it cuts into the middle of the Inland Empire, through cities such as San Bernardino, Colton, Moreno Valley, Redlands, Loma Linda, Hemet and San Jacinto, as well as near Riverside, Rialto and Fontana.
The Inland Empire is also particularly vulnerable to earthquakes because of a lack of seismic retrofitting. A Times investigation published in 2018 said there were hundreds of old brick buildings in more than a dozen…