It began as a distant rumble, the echo of underground thunder. Then massive subterranean jolts smashed homes like toys, pushed killer ripples through concrete and sent people screaming into the streets.

In 15 seconds, the Oct. 17, 1989, earthquake shook lasting changes into the San Francisco Bay area, hastening migration to the suburbs and humbling the audacious spirit that built and rebuilt a city atop active earthquake faults.A year later, tourists are returning to the city of sailboat vistas and hillsides dotted with pastel Victorian homes. But suburban dwellers who learned to live without the San Francisco-Oakland Bay Bridge are staying home.

"The other day, my husband and I drove over to the zoo and Golden Gate Park, and on the Bay Bridge I was saying, `It's the one-year anniversary and the A's are clinching. Let's pray.' It sure gave me the creeps," said C.J. Venness, who lives in Pittsburg, 35 miles east of the city.

The quake killed 67 people, 42 of them crushed when a segment of Highway 880 in Oakland crumbled like flaky pastry.

The massive tectonic shrug did in 15 seconds what planners and politicians could not. It wrenched thousands of car-crazy commuters from their automobiles and onto the Bay Area Rapid Transit system, which ran trains every three minutes to haul commuters into San Francisco while the bridge lay crippled.

About 20,000 of those commuters switched permanently to BART. Most flee the financial district early, whizzing back to the suburbs in time for dinner.

Shop and restaurant owners in San Francisco's hot spots say lingering quake fright has slowed business by as much as 30 percent.

Venness no longer shops as often in the city or frequents Candlestick Park, home of the San Francisco Giants. The earthquake, registering 7.1 on the Richter scale, struck at 5:04 p.m., moments before the third game of the World Series between the Giants and Oakland Athletics was to start.

"Most of us think about it, especially when we are on the Bay Bridge . . . It's a scary thought. We wouldn't want to be stuck in the city if something happened again," said Venness, a restaurant office worker.

Some professionals found they could work at home, and several large manufacturers from the Silicon Valley to San Francisco moved part of their operations east, fearing another temblor.

The tremors toppled hundreds of homes, from mountain estates overlooking Santa Cruz to shabby hotels in San Francisco's Tenderloin district.

Damage within the 100-mile radius is estimated at $6 billion, according to the state Office of Emergency Services.

The earthquake destroyed, but it also created heroes. Among them were the people of drug-riddled West Oakland, who ran from their housing projects to rescue suburban commuters crushed beneath concrete slabs.

When Highway 880 collapsed, "dozens of people who are considered an underclass were the first to climb up from the Cypress Gardens housing project to help their fellow citizens. They weren't an underclass that day; they were a class act . . . I will never forget the heroism of the poor people in West Oakland when they risked their lives to wrap blankets, perhaps their only blanket, around the injured," said Robert Maynard, publisher of The (Oakland) Tribune.

Experts with the U.S. Geological Survey say there is a 67 percent chance that at least one earthquake of 7 magnitude or larger will strike on one of the San Francisco Bay area's four major faults

sometime in the next 30 years. The region is striped with the San Andreas, Hayward, Calaveras and Concord faults.

Fear of the Really Big One, fear that emptied Fisherman's Wharf and luxury hotels last year, appears to have subsided among tourists.

Hotel business, down overall since last year, was up by 6.6 percent in July over the same month in 1989, according to Pannell, Kerr and Forster, an independent accounting company specializing in hotel trends.

But in the hardest-hit communities near the epicenter in the Santa Cruz Mountains, fences ring craters where offices and stores stood and homes hang off their foundations. Officials estimate itcould be a decade before the most serious damage is repaired.

In Santa Cruz, the Pacific Garden Mall resembles a bombed ruin.

San Francisco and Oakland have yet to begin major repairs on their ornate City Halls, shored up by timbers while officials lock horns with the Federal Emergency Management Agency over who will foot the bill. The tab for Oakland's alone will be $90 million.

Some 85,000 people applied for government earthquake grants or loans. One third of those who applied received grants from FEMA, which faced its most expensive disaster. The Small Business Administration received 25,000 applications but turned down one-third, prompting an outcry.

Most complaints came from the Marina District, the San Francisco neighborhood with the most physical damage. Fire gutted half a square block and tidy stucco buildings buckled and sagged onto the sidewalks.

About 3,000 people left homeless by the quake still sleep in shelters and parks. Only one of two dozen damaged transient hotels has reopened.

The Embarcadero Freeway, linking 2 million residents of Alameda and Contra Costa counties with Chinatown and Fisherman's Wharf, is cracked and deserted. City supervisors voted last month to tear it down.

Portions of Highways 101 and 280 remain closed, forcing cars onto city streets and causing traffic snarls as dense as those within days of the quake.