Residents from San Francisco to Los Angeles were shaken by Monday's quake, the first to cause fatalities in the state since a magnitude-6.7 temblor hit Northridge in 1994.
The bodies of two women were pulled from under the roof of Paso Robles' 1892 clock tower, which pitched into the street and crushed a row of parked cars in this San Luis Obispo County community of 25,000, some 20 miles east of the epicenter.
Mayor Frank Mecham said Tuesday that 82 downtown buildings had been identified as having at least some damage, and predicted that the quake's economic impact on the city would be significant.
"All we're waiting for is the governor to declare an emergency. Then we'll be asking for federal assistance," Mecham said.
Gov. Arnold Schwarzenegger visited the battered downtown Tuesday morning, and vowed aid for rebuilding. Schwarzenegger signed an emergency declaration that will allow San Luis Obispo County to get help from Sacramento as it recovers from the quake.
"At 11 a.m. yesterday this was an American main street, alive with energy. ... Today this is a site of devastation. But we will come together once again as Californians and as neighbors. We will rebuild this town square," Schwarzenegger said.
About 75,000 homes and businesses in San Luis Obispo and Santa Barbara counties lost power after the quake, but service had been restored to all but about 1,600 by Tuesday morning, were said Pacific Gas & Electric spokesman Bill Roake.
The main shock was centered in a sparsely populated area about 11 miles north of the coastal town of Cambria. It was followed Monday and early Tuesday by more than 80 aftershocks larger than 3.0, the biggest of which was estimated at 4.7, according to the U.S. Geological Survey. The total included seven aftershocks of 4.0 to 4.6 on Tuesday morning.
The state Office of Emergency Services said there was a 90 percent or greater probability that aftershocks of 5.0 magnitude or greater would follow in the next week.
By Monday night, search and rescue crews in Paso Robles had combed all seriously damaged buildings and were confident they had found all the quake's victims, though the owner of one car crushed in the rubble had not yet been located.
"We're out of rescue mode and now it's just going to be general debris removal," said Battalion Chief Scott Hall of the Ventura County Fire Department.
Earlier in the day, the bodies of Jennifer Myrick, 20, of Atascadero, and Marilyn Zafuto, 55, of Paso Robles, were found on the street outside a dress shop, police Sgt. Bob Adams said.
"It appeared as though they were trying to get away," he said.
About 40 people had minor injuries citywide, including a young boy who suffered a broken arm, said Adams.
"As soon as we felt the rocking and rolling and heard the glass starting to shake back and forth, we just started screaming, 'Get out! Get out!' and we just all ran for the door," jewelry shop manager June Ellart told CBS News' The Early Show.
When she got to a nearby park, she realized her parents and two customers hadn't gotten out of the store.
"I turned around and saw a big cloud of white dust and I just started screaming for my parents because they weren't around," Ellart told co-anchor Harry Smith. "And then after the dust cloud moved away for a second, we saw Nick and Pat [her parents] and the customers emerging."
The quake shook the Hearst Castle in San Simeon, the estate of the legendary publisher William Randolph Hearst. The castle reported no injuries and no immediate signs of any serious damage but was evacuated as a precaution. It was scheduled to be open Tuesday.
The quake also shook the federal courthouse in San Francisco, 165 miles to the northwest of the epicenter, and made the building's upper floors sway for about 30 seconds. People in downtown Los Angeles, 185 miles southeast, felt a sustained rolling motion.
"It was pretty sharp," said Sharyn Conn, receptionist at the oceanside Cypress Cove Inn in Cambria, population 6,200. "It really went on and on. I just got everyone under the door frames and rode it out."
Other than Paso Robles, damage appeared minor elsewhere in the region known for wineries and horse ranches. Several people were reported hurt by falling barrels at a winery, San Luis Obispo County authorities said.
Paso Robes' historic clock tower structure, sometimes called the Acorn Building, was made of wood and unreinforced masonry, a type of construction no longer allowed under modern building codes, Adams said.
Marilyn Curry watched the buildings collapse from her law firm across the street, then ran to a city park where people frantically searched for friends.
"There were people shouting outside 'Oh, my God! Oh, my God!"' she said. "Everybody was just shaking, then we were all just grabbing onto each other. There was a lot of hugging going on."
The quake was centered on a series of faults that run parallel to the San Andreas Fault, said Lucy Jones, scientist in charge of the U.S. Geological Survey office in Pasadena.
Monday's quake was the state's most powerful since 1999, when a nonfatal magnitude-7.1 quake struck the desert near Joshua Tree. The last one of a similar size in the area was in 1952, said Ross Stein of the USGS in Menlo Park.
The 1994 Northridge quake hit a densely populated area near Los Angeles and killed 72 people, injured 9,000 and caused an estimated $15.3 billion in insured losses.