LOS ANGELES — LOS ANGELES - A moderate earthquake, the largest in Southern California since 1999, struck 35 miles east of downtown Los Angeles yesterday morning. It swayed buildings and tossed food off grocery store shelves, but there were no reports of major injuries or damage.
The earthquake, which registered a 5.4 magnitude, was centered near Chino Hills in San Bernardino County and was felt as far east as Las Vegas and south to San Diego.
"This is moderate," said Erik Pounders, a geologist with the U.S. Geological Survey in Pasadena. "Which means it was strong enough to be felt, but wasn't even powerful enough to knock everything off your desk."
Still, cell phone lines were jammed throughout the region as people frantically made calls in the moments immediately after the jolt. Officials in Gov. Arnold Schwarzenegger's emergency management office urged Californians to free the lines for emergency use.
State and local officials immediately raced to inspect bridges, levees and other major infrastructure projects but found only a water main break. Train service in many areas was disrupted as the inspections continued, and at the Disneyland Resort in Anaheim, visitors were taken off rides. Inspections there yielded no reports of damage, officials said.
"This earthquake reminds us yet once again that in California we have to be prepared for everything and anything," Schwarzenegger said at a news conference in Los Angeles.
Some schools and office buildings were evacuated temporarily as people braced for the roughly 50 aftershocks by midafternoon, one of which registered at 3.8. The Los Angeles City Council, meeting downtown, adjourned briefly to regroup after the event.
The quake began slowly at about 11:40 a.m. and continued for several disarming seconds. Many residents experienced an eerie, dizzying sensation of having rolled from side to side on rollers that are common in high-rise buildings retrofitted to withstand earthquakes, which leave buildings swaying for several seconds after a quake.
Denise Cattern, a spokeswoman for Chino Hills, a suburb of about 80,000, said residents and businesses were reporting lots of things falling from walls and shelves.
"Our nerves have been rattled," Cattern said.
Jessica Chang, 12, was in class working on a math problem in Chino Hills when the shaking began. She said a vase fell on her head but she was not injured.
"When it started, I felt the shaking under my feet," she said. "I thought I was going to die. But my teacher told us to calm down." Her brother, Jayden, 5, piped in that he thought it was a "Tyrannosaurus rex walking."
The aftershocks cracked the walls and floors of homes and buildings in nearby Diamond Bar, said Lt. John Saleeby, the watch commander in the Los Angeles County sheriff's office in that town.
Elizabeth Cespuglio, 17, of Corona, about eight miles from the epicenter, was watching television and working on her computer when the shaking began. She ran to a doorframe, as experts advise.
"I always kind of liked quakes when they were tiny," she said by telephone. "But after it lasted longer, it kind of freaked me out." Two pictures fell from a wall in an adjacent bedroom but they did not break, and she did not see any other damage to the home. The quake was the largest in Southern California since a 7.1 magnitude quake hit an unpopulated area of the high desert in 1999.
The last powerful earthquake in urban Los Angeles - among the most seismically active regions in the world - struck in 1994 and was centered in Northridge, a section of the city in the San Fernando Valley.