LOS ANGELES — A strong earthquake with a preliminary magnitude of 5.4 shook large parts of Southern California on Tuesday, rattling a swath from Ventura County to San Diego.
The quake shook downtown L.A. buildings and was felt as far east as Palm Springs.
It was centered near Chino Hills, about 30 miles east of Los Angeles, the U.S. Geological Survey said.
There were no reports of major damage or injuries. But the Los Angeles Police Department reported minor structural damage at the Los Angeles County-USC Medical Center.
The magnitude of the quake was originally set at 5.8. But officials at the California Institute of Technology downgraded it to 5.4 and said they doubted that the temblor caused major structural damage.
Kate Hutton, a staff seismologist at Caltech, said 11 aftershocks were recorded, with 3.8 being the largest and only one felt.
“Most everyone in the L.A. Basin felt it,” Hutton said. “Things will have fallen off shelves. . . . There could be some cases of cracked plaster and maybe broken windows, but not structural damage, which is when a building is compromised.”
Gov. Arnold Schwarzenegger activated the Office of Emergency Services, and officials urged people throughout Southern California to cut back telephone use because the system was being “maxed out” and putting at risk those who needed 911 services.
Raja Mitwasi, chief deputy director of the California Department of Transportation office in Los Angeles, said traffic on the county’s highway system was not disrupted. He said Caltrans also was inspecting highway bridges and pavement.
“So far, there is nothing visible. We don’t even see minor damage,” Mitwasi said. Sheriff’s officials responded to multiple calls from people concerned because their house alarms had been activated. They also had heard many reports of groceries flying off the shelves at supermarkets.
Orange County also felt shaking, and officials were checking reports of possible minor runway damage at John Wayne Airport.
“It’s the first time in my life I actually got under my desk,” said Anaheim Police Sgt. Ken Seymour, a Southern California native.
