A magnitude-3.3 earthquake rattled parts of San Bernardino and Riverside counties early Friday and also caused shaking east of San Diego.
There were no immediate reports of damage after the quake, located in the Loma Linda area, part of an active seismic region east of Los Angeles. The quake was reported at 7:14 a.m.
Weak shaking was reported in Riverside, San Bernardino, Rancho Cucamonga, Fontana, Corona and nearby areas. The USGS also received a report of shaking in Fallbrook, which is about 80 miles south of Loma Linda.
The Inland Empire is home to the San Jacinto fault, one of the region's most active with a history of strong quakes. It runs through San Bernardino, Loma Linda, Redlands and other IE communities and was the center of a magnitude-5.2 quake in June 2016 that triggered hundreds of aftershocks.
The fault, which runs from the Cajon Pass to the U.S. border with Mexico, also generated the 1987 Superstition Hills earthquakes about 90 miles east of San Diego. The largest of those quakes measured magnitudes 6.5 and 6.7 and caused significant damage in extreme southeastern California.
In July 1923, a magnitude-6.3 earthquake rattled the region, damaging chimneys and windows. The San Bernardino County Hospital and the Hall of Records were badly damaged, according to Caltech.
Two people suffered critical injuries, but no fatalities were reported. Shaking was reported as far away as Los Angeles and Santa Barbara.
In March 1937, a magnitude-6 quake reported near the fault was called the Terwilliger Valley Earthquake, which caused similar damage. The 1980 quake caused a landslide that led to a closure on Highway 74 between Spring Crest and Palm Springs.