O.C. Shook but Emerged Unscathed : Impact: Damage reports were few, but a lot of nervous systems underwent some serious episodes. One person in Anaheim Hills sustained minor injuries.

Nerves were jolted, windows shook and burglar alarms went off. But Orange County residents by and large escaped Wednesday’s 5.5 temblor with nothing more than a queasy reminder that they live in earthquake country.

“My heart is still in my throat,” said Dixie Wilson, a Fullerton housewife who was having tea in her kitchen when the earthquake struck at 3:43 p.m. “I thought maybe, just maybe, this was it, the Big One. Thank God it wasn’t.”

Damage was minor around the county--bottles and cans were knocked from grocery shelves, books fluttered to the floor in several libraries and a vase tipped over and shattered in Brea City Hall. Some panes of glass were reported broken at West Municipal Court in Westminster and some cracks in concrete were spotted at county fire stations in Mission Viejo and Midway City.

Caltrans late Wednesday was inspecting a mile-long crack about three inches wide between the northbound fast lane of Interstate 5 and the center divider near Jamboree Road in Irvine. It was not known whether recent freeway repair work or the quake caused the crack.

County officials activated the Emergency Operations Center for several hours but then closed it after determining that there was no serious damage.

Apparently only one person in Orange County, a hospital employee in Anaheim Hills, was injured in the strong quake. Gilbert Rabuco, 31, fell in an elevator at Kaiser Permanente Hospital. He suffered minor bruises and was temporarily stunned--a condition shared by scores of county residents shaken to attention by the strongest temblor in Southern California since the 5.9-magnitude quake in Whittier in 1987. Rabuco was treated and released.

Wednesday’s jolt and roll left some residents gasping and searching for adjectives.

“Boy, it was something! I’m still sick from it, “ said Laura Williams, a clerk at Via Lido Drugs in Newport Beach.

Linda Bonniksen, a Pacific Bell spokeswoman, was just completing one of the company’s periodic earthquake drills with about 45 other employees when the firm’s emergency operation center in Tustin began rolling.

“It was eerie, very eerie,” she said. “The coincidence stunned everybody.”

The quake, centered in the Upland-Pomona area about 30 miles from north Orange County, delivered a geologic shiver felt from La Habra and Seal Beach to the steps of historic Mission San Juan Capistrano. A block away from the mission at the Swallows Inn, cement layer Dan Pederson hoisted a beer and toasted the “shake as a perfect cap” to his workday.

“It’s the most excitement I’ve had all day,” he laughed. “I’m a native, so this is nothing new. But the new folks, they get real green around the gills.”

Just ask Donna Santa Cruz, a receptionist at Bowers Museum in Santa Ana, who moved from Kentucky to California a year ago and had never experienced an earthquake.

“It was frightening. I was terrified,” she said. “My stomach was shaking along with the earthquake. I’m just freaking out.”

The quake was strongest in North Orange County, where officials and residents described it as a bumpy, jerky motion, punctuated by several jolts.

It lasted about 15 seconds, long enough--and intense enough--to cause high-rise buildings to sway and to prompt Disneyland officials to shut down all major attractions, including the Matterhorn, Space Mountain and Splash Mountain to inspect for damage. None was found, but visitors to the Magic Kingdom received an added thrill.

“When I first heard the rumbling, I thought there was a ride coming from behind me,” said Karen Bowers, a Washington State tourist who was in line outside the Space Mountain ride. “It kept coming. . . . I then realized that I was in a possible earthquake. The first thing that flashed in my mind was the San Francisco earthquake.”

Unlike the 1989 Bay Area quake, utilities in Orange County were largely unaffected by Wednesday’s temblor. There were no reports of electrical or gas interruptions, and telephone service, for the most part, was normal.

But similar to the initial hours of the 7.1-magnitude San Francisco quake, callers trying to reach friends and relatives in Orange County reported some delays getting through as the phone company’s “call-blocking” system kicked into operation. To prevent phone lines from overloading, computers randomly block calls for several seconds to spread the load.

Southern California Edison, operators of the San Onofre Nuclear Generating Station just south of San Clemente, reported an “unusual event”--the lowest level of alert--to the Nuclear Regulatory Commission.

“We are inspecting the facility now,” Edison spokesman Bob Goodlow said. “Units One and Two were in operation at the time of the quake, and they are still on line. We have no major outages.”

Despite the quake’s strong shake locally, scientists said the epicenter was too far and the magnitude too small to do major damage in Orange County. Medhat Haroun, chairman of UC Irvine’s department of civil engineering, also said that damage was minimal because the quake apparently did not occur on a major fault, according to initial seismic reports.

If the temblor had been on the Newport-Inglewood Fault that runs near the coast from Newport Beach to Beverly Hills, damage could have been more severe. Experts say a 7.3-magnitude quake--nearly 20 times the size of Wednesday’s jolt--would cause $20 billion in property damage in Orange County.

“It would be disaster for us,” Haroun said.

It wasn’t, and Tom Bratton of Anaheim is thankful for that. He was in line at the Anaheim post office waiting to buy stamps when “everything started wobbling.”

“Next thing I know, I’m the first in line,” he said. “The four people in front of me had scattered out the front door.”

At John Wayne Airport, Seattle businesswoman Nita Hamilton was waiting for a flight in the American Airlines lounge when the quake hit. Hamilton was in San Francisco when last October’s quake rocked the Bay Area, and Wednesday’s shake was a sober reminder.

“My first thoughts were, ‘Oh no! not again!’ ” she said.

Airport officials turned on television monitors in lounges, and many travelers crowded around to watch news of the quake. An initial inspection of the new passenger terminal under construction turned up no signs of damage.

Schools throughout the county will open on schedule today, but as a precaution, officials in most districts scoured campuses looking for cracks, broken windows or water lines.

“School was not in session when the quake struck, which is fortunate,” said spokesman Alan Trudell of the Garden Grove Unified School District. “The custodial staff will survey the sites.”

At UC Irvine, Garland Parten, executive assistant to UCI’s Academic Senate, said, “I don’t think I’ve ever felt one that bad here.” She was in her office on the fourth floor of the Social Science Tower when the quake hit.

“It seemed to me like it was kind of a sharp one, and it lasted an awfully long time. The drapes here were swinging back and forth,” she added.

In Santa Ana, at the county Hall of Administration, which was reinforced in the early 1980s after it was deemed seismically unsound, Assistant Sheriff John (Rocky) Hewitt was conducting a news conference when the quake struck.

While Hewitt was in mid-sentence, lambasting the American Civil Liberties Union for filing complaints against the Sheriff’s Department’s jail operations, five reporters glanced at one another, then got up and ran out the Santa Ana Boulevard entrance of the building.

Hewitt, unfazed, walked out a minute later and finished reading his prepared statement on the sidewalk.

For Kirsten Bulmer, a Seal Beach resident, the earthquake was enough to make her think about moving out of California.

“I’ve never been so scared in my life,” she said. “If I feel one stronger than this, I’m a plane ticket out of here.”