THE severe earthquake that rumbled through the San Fernando Valley yesterday has shown how vulnerable Southern California is to a major temblor.
The quake, measuring 6.6 on the Richter scale, hit early yesterday morning and caused widespread damage in the heavily populated valley just north of downtown Los Angeles - and in some areas beyond.
It knocked down buildings, ruptured gas lines, burst water mains, buckled large sections of freeway - and jolted a Southern California populace already wary from fires and previous natural disasters. According to early reports, at least 10 people died.
For all the damage, though, it could have been worse. By hitting at 4:30 a.m., the earthquake struck freeways that were relatively free of traffic.
``The city is fortunate this happened in the early morning hours. If it had been during the day, we would have had tens of thousands of people in high-rise structures,'' a police spokesman said.
To be sure, Californians awoke to some painfully familiar images: freeway sections snapped off, miles of rumpled roadway, and some parking structures collapsed. But because there were relatively fewer commuters, there were far fewer fatalities on the freeways than in the 1989 San Francisco quake, which hit at rush hour.
Some of the most immediate problems were caused by damaged utility lines. Houses were blown apart in gas explosions and cars were hurled off freeways when the quake hit.
The quake centered in the San Fernando Valley was the biggest since a 1992 temblor that shook high-rise buildings in downtown Los Angeles and caused minor damage over a widespread area. That quake measured 6.3 on the Richter scale.
Initial estimates of the magnitude of yesterday's quake varied. The California Institute of Technology reported that the quake measured 6.5; the Alaska Tsunami Warning Center in Palmer, Alaska, put the quake's preliminary magnitude at 6.7.
``It's the worst earthquake I've ever seen,'' said Jamie McDowell, a longtime resident of Sherman Oaks, a suburban community close to the epicenter of the quake.
Los Angeles Mayor Richard Riordan quickly declared a state of emergency and called for disaster relief:
* At least a half dozen major highways, including the Santa Monica Freeway and Interstates 5 and 14, suffered extensive damage, which officials said could take months to repair.
* Store fronts were shattered along Ventura Boulevard, the main retail drive that runs the entire length of the valley.
* Water from broken mains shot 30 feet in to the air and water flowed down streets and out of stores.
* Fires, apparently caused by natural gas pipeline ruptures, were reported in at least 50 homes and subdivisions.
* The Los Angeles Police Department reported instances of looting.
Volunteers were out in force within minutes of the quake to help direct traffic around fires. Carlin Muzzarelli, a volunteer member of the Los Angeles city fire department waving cars around a burning building at the corner of Woodman and Ventura Boulevard, said that the number of gas leaks was the biggest concern.
Yesterday's quake lasted for about 30 seconds or more, and aftershocks followed within minutes.
Residents along the valley quickly evacuated houses and huddled in cars or in blankets on their front lawns. Dishes fell off shelves, pictures were askew, and there were scattered power outages.
``We lost a chimney and some walls, but we're safe, and that's what's important,'' says David Collins, a Sherman Oaks resident.
``It's time to get the camping supplies out,'' said Quinton Clark, also a Sherman Oaks resident. ``The whole house was shaking and all I could hear was breaking glass.''
Inside homes, many residents coped with broken glass and collapsed walls and chimneys.
The quake was felt in Santa Barbara to the northwest, Bakersfield to the north, Las Vegas to the northeast, and San Diego to the south.
The quake also was felt strongly in Encino, 50 miles east of Los Angeles in San Bernardino County. The Federal Emergency Management Agency said yesterday it had opened a regional operations center in San Francisco to help cope with effects of the earthquake.
``FEMA is working real close with the State of California's emergency operations services,'' Gary Belcher, an operations specialist at FEMA's national coordination center, said in a telephone interview with Reuters.
He said federal employees were helping gather information, assess needs and coordinate the official response.
The quake that jolted California this morning temporarily closed Los Angeles International Airport, forced airlines to scrap or reroute flights and disrupted the entire domestic air-travel network.