Aftershocks Rock Valley; Detours to Freeways Open : Aftermath: One temblor measures 5.0, sending some residents back into shelters. But recovery gains steam and Shalala announces $28 million more in assistance.

A powerful string of pre-dawn aftershocks--including a magnitude 5.0 temblor--rattled a sleeping Los Angeles on Saturday, putting police on temporary alert, buckling already weakened structures and sending some nervous residents scrambling back to shelters.

But the strongest aftershock to hit the San Fernando Valley in 10 days was not enough to impede recovery efforts, as detours were opened around collapsed freeways and U.S. Department of Health and Human Services Secretary Donna E . Shalala announced she was making available an additional $28 million in federal aid.

Touring the quake damage at Los Angeles County/USC Medical Center, Shalala also said she had persuaded the Treasury Department to issue thousands of Social Security checks a week earlier than usual to ensure that the elderly receive their benefits on time.

“We are taking very rigid federal programs and we are making them flexible,” she said. “We can’t do everything by the book in a disaster.”

The day’s other developments included:

* The barrage of aftershocks--nine greater than 3.0 were recorded in a seven-hour period Saturday morning--snapped a water main in Northridge, knocked out street lights in Santa Monica and, crumbled what was left of a four-story parking structure at Cal State Northridge.

* Although more than 5,000 people remained at 31 Red Cross shelters, the population at five Salvation Army tent cities had dwindled to less than 600 and National Guard troops began dismantling the encampments at Lanark, West Valley and Valley Plaza parks.

* Caltrans opened a detour around the damaged Golden State Freeway to the Santa Clarita Valley, restoring California’s primary north-south route to 40% of its capacity. Meanwhile, engineers closed two lanes on the bridge connecting the westbound 134 Freeway to the northbound Ventura Freeway to shore up a weakened column.

* Red Cross officials in Northridge opened what one worker called the “Wal-Mart” of disaster centers: a circus-sized tent full of case workers who can process up to 1,000 people a day--10 times that of a normal Red Cross center.

* The state Department of Health Services and the Department of Water and Power announced that all water in the city of Los Angeles is safe to drink. Residents no longer need to boil or disinfect water, but they are urged to run their faucets for several minutes to flush out the pipes.

* In the Santa Clarita Valley, the Newhall County Water District also lifted its boil-water order, but customers of the Santa Clarita and Valencia water companies were advised to continue doing so.

* Seeking to crack down on fraud, county welfare officials began imposing a three-day waiting period for emergency food stamps and said all offices would be closed today while they set up a computer system to help weed out bogus claims. On Friday, police arrested a man for allegedly selling several hundred dollars worth of food stamps near a downtown relief center.

* Amid growing complaints that landlords have been using the earthquake to oust tenants and raise rents, city officials urged apartment-dwellers to be aware of their rights and not be pressured into relinquishing undamaged units.

The number of quake refugees in tent cities dropped to 587 Friday night, and National Guard officials were making plans to close one or more of the five tent encampments during the weekend and to send quake victims to other sites.

By late Saturday, at Lanark Park in Canoga Park, West Valley Park in Reseda and Valley Plaza Park in North Hollywood had been taken down.

Lt. Brian Anderson, a public affairs officer with the California Army National Guard, said more than 400 people stayed in the tent camps at Reseda Park and Winnetka Recreation Center, while the encampments at Lanark, West Valley and Valley Plaza each housed fewer than 100 people Friday night.

“The order is start consolidating down and let Winnetka be the last tent site,” Anderson said.

At their peak, the tent camps sheltered 4,780 people. Meanwhile, 31 Red Cross shelters throughout the quake zone housed 5,244 people Friday night--less than half the number at the height of the disaster.

At the tent cities, the flurry of aftershocks sent some recent campers, who finally had worked up the courage to return home, scurrying back to the shelters.

“In my apartment, there is always something moving,” said Rosa Ana Moreira, 38, who sought refuge with her 10-year-old daughter Saturday morning at the Winnetka Recreation Center.

Since the Jan. 17 quake, Moreira’s family had been sleeping in a car outside their Northridge apartment building, which was deemed safe by inspectors but seemed too precarious to her. On Friday, for the first time since the quake, she summoned the courage to spend the night inside. But the early morning aftershocks only confirmed her doubts.

“I’m going to stay here until I feel safe,” she said at the tent city, “until there is no more trembling.”

U.S. Geological Survey seismologist Lucile M. Jones said the aftershocks were within “a normal range,” even though they have been both a little more numerous and more powerful than is normally expected from a 6.6 temblor.

Jones, in a briefing at the Caltech Seismological Laboratory, said the chances of another magnitude 5.0 aftershock in the next week are about one in seven, and the chances of another one in the next year are about 50-50. She added there is little immediate concern that an earthquake larger than 6.6 will grow directly out of the Northridge quake.

“This is just the earth settling into its new position,” she said. “Large blocks have moved, and the earth is still readjusting.”

The 5.0 aftershock at 3:20 a.m. was the strongest since President Clinton was jolted by a 5.1 quake while visiting Los Angeles on Jan. 19. But Shalala, who has been surveying earthquake damage with other top federal officials, said she slept right through it.

Joking with her aides at a Burbank hotel, she said she hoped nobody would think that was “an indication of my responsiveness to this disaster.”

Shalala was accompanied by Federal Emergency Management Agency Director James Lee Witt, Social Security Commissioner Shirley Chater and Assistant Secretary for Aging Fernando Torres-Gil, who joined the secretary to make certain that senior citizens are not overlooked in the federal response to the disaster.

At the Mid-Valley Comprehensive Health Center in Van Nuys, Shalala watched as workers tried to dry out medical records with portable fans. In a soothing exchange with a 6-year-old boy whose face had been cut by falling glass during the quake, she asked: “Were you in your bed during the earthquake? Was it scary?”

“We’re sleeping in the truck still,” Michael Miller responded.

The boy then turned the tables, poking Shalala in the chest with an orange Popsicle so that she would look at the scar on his nose. Then he asked why the President hadn’t come instead of her.

“He sent me because he didn’t have a voice,” said Shalala, apparently referring to Clinton’s hoarseness after his State of the Union address. “But he’s worried about you guys.”

Touring County-USC Medical Center, Shalala shuffled through a maze of cracked walls and buckling support columns, passing patients on gurneys in hallways. She said federal funds should be used to foster the hospital’s long-range development, rather than patching up outdated structures.

“We ought to see this as an opportunity to plan for health care in the 21st Century, not rebuild what we have,” she told Witt.

Making a Financial Killing

Even as relief poured in, officials expressed concerns about abuse.

Wary of fraudulent claims, authorities began instituting a 72-hour waiting period for earthquake victims seeking emergency food stamp assistance. Moreover, officials said all food stamp centers will be closed today to set up computer equipment designed to ferret out those who do not qualify for the program. Offices will reopen Monday at 7 a.m.

“It allows a lot more time, not only to complete checks, but to look at information on the application a lot more closely, to see if there are any inconsistencies,” said Dick Montoya, spokesman for the U.S. Department of Agriculture, which runs the food stamp program.

In addition, officials reduced the number of sites from 29 to 16 in an effort to assist law enforcement authorities concerned about controlling crowds of 1,000 or more who have waited in line for hours, hopeful of getting coupons that can purchase food at grocery stores and markets.

The Red Cross “Supercenter” that opened in the parking lot of the severely damaged Northridge Fashion Center is being tested for the first time, said Roberta King, a Red Cross spokeswoman.

Michelle Shabani, 22, who has been living in a U-Haul truck with her parents since their Northridge apartment was condemned Jan. 17, said she was thankful to be out of the long lines and off of the phone. “We went to the Winnetka Park and the lines were so long, they told us to call,” Shabani said. “So we started calling and we got through but they said to wait until we heard from them--that was 10 days ago and in the meantime we have nothing anymore.”

Mother Nature Helps Out

Saturday’s aftershocks, centered near Chatsworth, sent engineers scrambling to assess the damage.

The parking structure at Cal State Northridge was finished off by the powerful series of temblors.

“Demolition will be just a little bit easier now,” said Kaine Thompson, a spokeswoman for the university. “Mother nature is helping us out.”

After a preliminary overview of the campus, officials found that considerable debris from the battered overhang of the Delmar T. Oviatt Library had also tumbled to the ground. Crews began removing it Saturday with cranes. The South Library, which was already severely damaged in the initial quake, shifted laterally during the aftershocks. Inspectors planned to survey the campus again Monday.

The aftershocks also forced Los Angeles Unified School District officials to reinspect the 14 Valley campuses set to reopen Monday.

Although surface cracks in walls grew slightly at some schools, the aftershocks had no effect on the scheduled reopenings.

Caltrans engineers, concerned that some support columns may have been weakened by the aftershocks, began shoring up the connector bridge between the 134 and 101 freeways.

The Glendale Boulevard bridge over the Golden State Freeway also was closed for a few hours after inspectors noticed that a joint had slipped, but later determined that it posed no threat.

None of that dampened the excitement of officials who gathered Saturday to open a three-mile stretch of The Old Road, which now serves as a detour around the damaged Golden State Freeway in the Newhall Pass area.

On Friday, Caltrans also reopened the southbound truck route from the Antelope Valley Freeway to the Golden State Freeway, allowing traffic to bypass congested Sierra Highway.

Times staff writers Abigail Goldman, Nancy Hill-Holtzman, Jesse Katz, Myron Levin, Patrick J. McDonnell and special correspondent Susan Byrnes contributed to this story.

COMING MONDAY: An 8-page Valley Edition special section will recapture photo images of the Northridge earthquake.