Aftershock of 5.0 Rattles L.A.; U.S. Allots More Aid : Aftermath: Barrage of strong temblors sends some residents back into shelters. Administration’s Donna Shalala announces $28 million in additional relief.

A string of powerful 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 city 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 Shalala announced that 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 magnitude 3.0 were recorded in the five hours between 2:03 a.m. and 7 a.m.--knocked out street lights in Santa Monica, snapped a water main in Northridge and crumbled what was left of a four-story parking structure at Cal State Northridge that was slated for demolition.

* Seeking to crack down on fraud, county welfare officials began imposing a three-day waiting period for emergency food stamps and said all offices will be closed today while they set up a computer system to help weed out bogus claims. On Saturday, about 10 people were arrested for allegedly “ripping the system off” by buying--and reselling--the food stamps outside a South-Central Los Angeles check-cashing store, Agriculture Department officials said.

* Amid growing complaints that landlords have been using the quake 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.

* Caltrans opened a detour around the Golden State Freeway in the Santa Clarita Valley, restoring California’s primary north-south route to 40% of capacity. A bridge near the interchange of the Golden State and Antelope Valley freeways was dynamited in preparation for emergency reconstruction of earthquake-damaged spans. Meanwhile, engineers closed two lanes on the bridge connecting the Ventura Freeway to the Hollywood Freeway to shore up a weakened column.

* The state Department of Health Services and the Department of Water and Power announced that all water in Los Angeles is safe. Residents no longer need to boil or disinfect water if they had been living under those restrictions, but they are urged to run their bath or shower for several minutes to flush out the pipes.

* 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 Park and West Valley Park. Still, the aftershocks sent some recent campers, who finally had worked up the courage to return home, scurrying back to 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 spent 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 more numerous and more powerful than normally expected after a magnitude 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 that there is little immediate concern that an earthquake larger than 6.6 will result directly from 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 strongest since President Clinton was jolted by a 5.1 quake while visiting Los Angeles on Jan. 19, two days after the 6.6 temblor. But Shalala, who has been surveying earthquake damage with other top federal officials, said she slept right through it.

Joking with 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.

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 help 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.

At the next stop, the Mid-Valley Comprehensive Health Center in Van Nuys, Shalala visited a 6-year-old boy whose face had been cut by flying 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 asked why the President had not come personally.

“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.”

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 stamps. 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 at 7 a.m. Monday.

“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 be used to purchase food. Scuffles have broken out at several sites.

To compensate for the closures, four large centers will be opened at Dodger Stadium, Whittier Narrows Recreation Area, Victoria Park in Carson and the County Building on the Eastside.

Meanwhile, amid increasing reports that landlords were using the earthquake to oust longtime tenants, city officials urged apartment dwellers not succumb to owners’ pressure tactics.

“We have some unscrupulous landlords who have found an opportunity for a financial killing,” said Councilman Zev Yaroslavsky, who was among those participating in a news conference designed to put tenants on alert.

Feeling cheated by price-gouging merchants after the quake, some Valley residents took matters into their own hands.

On Saturday, they returned to stores where they said they had paid inflated prices for water and batteries, confronted the shopkeepers and demanded that they sign an agreement pledging to treat customers fairly.

Two merchants said they knew of no such abuse, but signed the agreement anyway. However, at a Pacoima gas station, the clerk refused, saying she wanted to consult her attorney.

Mother Nature Helps Out

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

The CSUN parking structure, which partially collapsed in the initial quake and had been crumbling slowly ever since, was finished off by the powerful aftershocks. The four-story structure was reduced to one story.

“Demolition will be just a little bit easier now,” said Kaine Thompson, a campus spokeswoman. “Mother Nature is helping us out.”

The aftershocks also forced Los Angeles Unified School District officials to reinspect 14 San Fernando Valley campuses set to reopen Monday. Although surface cracks in walls grew slightly at some schools, the aftershocks had no effect on the reopenings.

“It may look a little worse, but it will not adversely affect the health and safety of the children,” said Doug Brown, director of school facilities for the district.

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

“We want everybody to know that California is open and ready for business,” Caltrans spokeswoman Margie Tiritilli said.

Meanwhile, Red Cross officials opened what one called the “Wal-Mart” of disaster centers, which can handle up to 1,000 people a day. The center is in the parking lot of the severely damaged Northridge Fashion Center.

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