Earthquake jolts 'lucky' Los Angeles

An earthquake struck just east of Los Angeles on Tuesday, rocking tall buildings and rattling nerves across Southern California, but causing no serious injuries or major structural damage.

The quake hit at 11:42 a.m. local time (7: 42 p.m. BST) about 30 miles (48 km) east of Los Angeles in suburban Chino Hills and registered magnitude 5.4 - making it the strongest seismic event centred near America's second-largest city since the 6.7-magnitude Northridge quake in 1994.

It was followed in the next few hours by more than 50 aftershocks, the largest measuring 3.6, and geologists said there was a small chance it could be a foreshock to a larger earthquake.

"I think we were very lucky with this one," Gov. Arnold Schwarzenegger told a news conference in Sacramento, adding he called his Los Angeles-area home to speak with his wife, Maria Shriver, immediately after the quake.

Magnitude 5 quakes are considered moderate but are still capable of causing damage. The U.S. Geological Survey said Tuesday's quake was shallow, about 8.5 miles (13.6 km) deep.

Across Southern California, the temblor was felt as a strong jolt, swaying tall buildings in downtown Los Angeles and Orange County and sending office workers into the streets.

"I immediately went and stood under a doorway," said Rachel Feldman, a 27-year-old attorney who works in the 75-story US Bank Tower in downtown Los Angeles, the tallest building in the western United States.

Sara Phillips, 28, also an attorney in the US Bank Tower, said: "I wasn't scared. The building is on rollers so it made me feel like I was going to barf."

Elsewhere, water mains broke and goods fell off store shelves but no serious injuries were reported. Airports, ports, power grids and nearby nuclear power plants all reported no structural damage or interruption in service.

The ground shook for hundreds of miles (km) and was felt as far south as the Mexican border and east to Las Vegas and Flagstaff, Arizona.

'IT WAS A HARD SHAKE'

In Chino Hills, where the shallow quake struck some 7 miles (12 km) below the surface, spokeswoman Denise Cattern said no reports of damage of injury were reported in the city of 80,000 but that residents were unnerved.

"Most people agreed it was the biggest earthquake they ever felt," she said.

"The first thing we thought was that LA went down and we were on the other end of it. It was a hard shake and it lasted about 30 seconds," said Doug Sparkles, who was shopping with his wife, Debbie, near Chino Hills when the quake hit.

The Northridge quake, which struck just before dawn on January 17, 1994, killed 57 people, collapsed an apartment building and caused billions of dollars in damage. City officials have since strengthened building codes for new construction and required retrofitting of older buildings.

"In California, fortunately because of our good building standards, we would not expect to see structural damage with a (magnitude) 5.4," said Kate Hutton, seismologist at the California Institute of Technology, or Caltech.

Caltech experts estimated that Tuesday's quake released only 1 percent of the energy unleashed by the 1994 disaster but they noted there was a 5 percent chance the Chino Hills quake was a foreshock to a larger seismic event.

"I think we are as prepared as anyone can be. I think we're better prepared than any other state for emergencies like that," Schwarzenegger said.

In Anaheim, 40 miles (64 km) south of L.A., workers at Disneyland removed visitors from rides but the world-famous amusement park remained open and rides were resuming.

Los Angeles is the most populous city in California and the second-most populous urban area in the United States. According to 2000 Census Bureau figures, about 3.6 million people live in the city of Los Angeles, while Southern California is home to more than 20 million people.