Earthquake collapses historic building, killing 2
Tremors felt along much of California coast
Rescuers dig for survivors at the site of a building collapse in Paso Robles, California.
CNN's Frank Buckley reports on the quake that killed two in California.
Rescue workers search for casualties in a quake-damaged building.
Ross Stein of the U.S. Geological Survey says the quake hit a sparsely populated area.
PASO ROBLES, California (CNN) -- Two people died when a historic building collapsed in Paso Robles after a strong earthquake jolted the central California coast Monday and sent tremors from Los Angeles to San Francisco and beyond.
The quake registered a preliminary magnitude of 6.5 when it hit about 11:15 a.m. (2:15 p.m. ET), the U.S. Geological Survey said.
Its epicenter was about six miles northeast of the coastal town of San Simeon, about 240 miles north of Los Angeles and 200 miles south of San Francisco. But it occurred at the relatively shallow depth of about five miles and was felt across a wide swath of the state.
"We have reports of motion being perceptible from way south of Los Angeles to way north of San Francisco," said Bill Ellsworth, chief scientist of the earthquake hazards team for the U.S. Geological Survey in Menlo Park near San Francisco.
About 50 aftershocks with magnitudes of about 3.0 were reported within three hours of the original quake, Ellsworth said.
In about one in 20 earthquakes, an aftershock is more powerful than the original quake, he said and urged area residents not to enter structures that may have been damaged.
Scientists had no warning of the shock, which occurred in an area that has experienced a large number of small earthquakes in recent years, he said.
"It apparently occurred without any significant foreshocks, but this is not unusual."
In Paso Robles, about 30 miles inland, Jennifer Murick, 19, of Atascadero, and Marilyn Zafuto, 55, of Paso Robles, were killed by falling debris from the collapse of the city's landmark clock tower, police said.
Police and fire officials completed a search of the rubble late Monday with cadaver-sniffing dogs and determined that there were no additional casualties.
The tower was on a corner of a two-story building constructed in 1892. It was across from a municipal park and housed a jewelry store, said Madelyn Stemper, an accountant at a nearby office.
"A lot of the buildings across from the park in both directions are pretty well demolished," she said.
In all, 40 people sought medical attention in northern San Luis Obispo County, said Sgt. Bob Adams of the Paso Robles Police Department.
One person who was pulled from a destroyed restaurant called the House of Bread suffered a broken arm, but the other complaints were chest pains, heart and respiratory problems, he said.
The streets were packed with holiday shoppers at the time of the collapse.
"We're fortunate we didn't have any additional fatalities," Adams said.
Firefighters worked Monday night to shore up or tear down some of the 46 buildings damaged in the five square blocks of downtown Paso Robles, he said.
Another Paso Robles resident, Bijan Eskandanian, said he and his wife were walking down the street when the quake hit "like a shock wave in a bomb blast," he said. "It almost knocked us off our feet."
City officials said businesses and homes near downtown were destroyed by the quake, which ruptured gas and water lines. They urged residents to use bottled water for drinking and cooking until the city's water system can be checked and confirmed safe.
A hot springs well came uncapped in the quake, spreading a heavy sulfur smell over downtown.
Elsewhere, hospitals reported no patients arriving with injuries. A spokesman for Pacific Gas & Electric said about 40,000 customers were without power after the quake triggered rock slides that brought down power lines near San Luis Obispo.
No damage was reported at PG&E's Diablo Canyon nuclear plant, about 100 miles from the epicenter. A plant spokesman said operations continued uninterrupted.
Park rangers in San Simeon ordered evacuation of the Hearst Castle, the palatial home built by newspaper magnate William Randolph Hearst.
The castle is now a state historic site. Ruth Coleman, director of California's state park service, said no structural damage had been detected, but some artifacts from Hearst's extensive collection may have been damaged.
Mary Carson, executive director of the Chamber of Commerce in nearby Cambria, said the rolling lasted for what seemed like a minute.
"At first, it felt like a big truck was going by. Then it kind of rolled," she said.
"Things did fall off the shelves, a couple of windows broke and some ceilings came apart. But, as far as I can tell, I haven't heard of any injuries or severe damage."
Templeton resident Tony Vasquez said he was in the shower when the quake hit. He said he heard "a slight rumble, and then this enormous jolt knocked me down and actually sheared off the shower head."
"I never thought I'd have to wear a seat belt in the shower, " Vasquez said.
Brian Lassiege, a USGS geophysicist, said the quake was relatively shallow, striking about 4.7 miles below the Earth's surface. Lassiege said shallower earthquakes tend to inflict more damage.
USGS geophysicist Ross Stein said the last earthquake of similar size occurred along the same coastal area in 1952, but he said he was not sure on which fault the latest shake occurred.
"But we believe the earthquake occurred on the San Simeon fault not far from the Hearst Castle and Cambria," Stein said.
"This fault extends to the south where ... essentially one long fault that kisses the coastline all the way from where California takes its northward bend near Santa Barbara up to the Golden Gate."