YUCCA VALLEY, Calif. -- The earth continued to churn beneath the Southern California desert yesterday, destroying a commercial building, hindering repairs to disabled water systems and stoking the fears of people whose lives were jerked askew by the twin shakers that struck a day earlier.
Hoping that yesterday would bring relief from the terrifying tremors, desert dwellers instead were jolted by four major aftershocks that caused three dozen injuries, sparked two fires and prompted some rattled residents to plan extended vacations.
"I'm thinking of taking the Amtrak and going home to Mama for a while," said Darlene Puluti of Joshua Tree, Calif., a recent New Hampshire transplant who was among 600 people who ate free meals and sought consolation in emergency shelters yesterday.
Scientists, meanwhile, continued to puzzle over the remarkable earthquake sequence but disagreed over whether it portends a "Big One" on the San Andreas Fault. They agreed, however, that there is a 50-50 chance that an aftershock of 6.0 could occur this week.
Adding to the seismological intrigue, an unrelated, 3.9-magnitude earthquake centered under the Rose Bowl in Pasadena struck just before 4 p.m. yesterday.
Twelve hours earlier, a 5.6-magnitude temblor rolled across the Nevada desert, jostling casinos and hotel guests in Las Vegas. No injuries were reported and that shaker was said to be unconnected to those in California.
In the high desert of San Bernardino County, the biggest worry yesterday remained water and the searing desert heat.
More pipes were broken by the day's fiercest aftershocks, which struck in the morning and ranged from magnitude 4.9 to 5.4, and about 5,200 households were still without water at nightfall.
"The situation today is a lot worse than we thought it was," said Roger Duran, president of the Hi-Desert Water District.
Mr. Duran said that repairs to his system, which serves 4,000 homes in Yucca Valley, could take several days.
In Big Bear, Calif., the epicenter of a 6.5 temblor that rocked the mountain area three hours after the desert quake Sunday, yesterday's aftershocks caused no new structural damage. But the psychic trauma finally got to Michael Johnson.
"I ain't been this scared since I was a kid," said Mr. Johnson, a martial arts instructor who stands an imposing 6 feet 6 inches. "I never jump, I never panic in an earthquake. But now I do, because these tremors keep coming back."
As scientists sought to unravel the seismic details surrounding the quake sequence, officials continued their tally of damages. The human toll remained remarkably low, credited to the timing of Sunday's most powerful, 7.4-magnitude quake and its location in a sparsely populated area.
Joseph Bishop, 3 1/2 , who was crushed by falling fireplace bricks, was the lone fatality. Joseph, of Newbury Port, Mass., was visiting Yucca Valley with his parents, who were attending a high school reunion. The injury total rose to about 385 with the new aftershocks.
Property losses were estimated at $61.3 million for San Bernardino County and $81,000 for Riverside County. Those figures, however, were expected to rise as inspections continue. In San Bernardino County, 20 homes and 10 businesses were destroyed, and another 1,100 homes and 33 businesses were damaged.