As some merchants and homeowners continued sweeping up Monday after the earthquake that rolled across Southern California on Sunday, seismic experts concluded that the temblor could not be viewed as a precursor to the major quake expected to rock Southern California.
San Diego County authorities said the earthquake, centered in the Pacific 28 miles southwest of Oceanside, caused about $720,000 in damages, but there were no major structural problems reported.
The number of earthquake-related injuries climbed from 15 to 29 Monday. Most of those treated at San Diego-area hospitals complained of chest pains or suffered cuts, bruises and sprains while fleeing their homes during the early morning shaker, the second strong earthquake to hit Southern California in less than a week.
Anthony Cima, an 87-year-old man trapped for 11 hours under thousands of books that toppled on him in his room at a downtown San Diego residential hotel, was listed in serious condition at UC San Diego Medical Center, but seemed to be improving, a hospital spokeswoman said.
One woman, Arless Wilson, 55, of Chula Vista suffered a heart attack during the quake and died shortly afterward.
Seismic experts began the tedious task of poring over data gathered in the hours after Sunday's earthquake, which struck at 6:46 a.m. and was followed over the next 27 hours by 16 aftershocks. The quake, which measured 5.3 on the Richter scale and was the largest to rattle San Diego County since seismic monitoring began in 1932, was preceded by a milder shaker centered about two miles north of Chula Vista.
The largest aftershock came 16 minutes after the quake, and measured 4.5 in magnitude.
John Anderson, an associate research seismologist at University of California, San Diego, said the larger offshore earthquake had no connection with the Chula Vista quake, which was 3.0 in magnitude and rumbled through the area at 4:25 a.m., causing no damage. The two earthquakes occurred on different fault lines.
"Most likely, it's just an interesting coincidence that happened by random chance," Anderson said.
In addition, scientists said Sunday's tremors appeared to be unrelated to the 5.9 earthquake that struck the Palm Springs area a week ago, buckling roads, triggering rock slides and felling utility lines. That quake was the largest temblor to hit Southern California in seven years, causing nearly $6 million in damage.
"We cannot use these to make any predictions in terms of the time a major earthquake would hit," Anderson said. "Eventually, Southern California will have a big earthquake. Eventually, the San Andreas fault will have an 8. I don't know if that's going to be in 30 years or tomorrow or 100 years."
Sunday's quake was felt by residents from Santa Barbara to the Baja Peninsula, and as far inland as Yuma, Ariz.
At the San Diego County Office of Disaster Preparedness, reports of damage to homes and businesses continued to trickle in Monday. But officials said it appeared that the quake's toll on the county was relatively light.