Amy Frazier had lost her glasses and could see little but smoke and fire. She remembers the noise of helicopters hovering above. We're going to burn to death, she thought, but she just stared at a tangle of wires and debris. She doesn't know how she got out of the jetliner.

Her husband, Max, later told her she ran screaming down rows of corn in a field next to a runway. All she remembers is the mud on her white leather shoes. She kept wondering, How am I ever going to get them clean again?

She threw away her shoes because the mud wouldn't wash off, but for Frazier and the 183 other survivors of United Airlines Flight 232, the memories can't be cast away.

"Nothing is ever as fun as it used to be," Frazier says. "There are days when I just think it ruined my life."

It was a year ago today that the DC-10 jetliner lost an engine, suffered total hydraulic failure, and after a nerve-racking 40-minute flight, cartwheeled into flames at the Sioux City, Iowa, airport. One hundred and twelve passengers died.

In ways large and small, those who walked away from the three-quarter-mile gash of wreckage have seen their lives change. For some it was the pain of losing a loved one. For others it meant that the solid ground of their lives has been forever shaken. Even the jolt of potholes under the tires sends some back to the explosion of the tail engine. Others tremble at the mention of a disaster, any disaster, on television.

More than a few have redefined their values, finding more importance in family and friends than in business. They try to live in the present because for them the future is an iffy bet.

Many of those who beat the odds are returning to Sioux City today for a memorial reunion, a thank-you to the city of 82,000 that opened its arms to the dazed passengers who tumbled from the sky that hot afternoon last summer. Rescue workers still troubled by the tragedy, as well as friends and family still reeling from the blow, will join the survivors to remember the accident -- in the words of one witness, both a miracle and a disaster.

For the Fraziers, it will be the first trip they've taken in about a decade without Janice and Peter Cheng, who lived in Lisle, Ill., not far from the Frazier home in Wheaton. The two women spent nearly every day together; on weekends, the couples golfed. "We just didn't go any place without them," Amy Frazier, 52, says. "We were together so much people called her Amy and me Jan."

Last summer, for their golfing trip with the Fraziers, the Chengs used their accumulated frequent-flier points to upgrade their tickets to first class. No one in first class survived.

"I get very aggravated at people who complain about the small things in life that don't mean anything," says Amy Frazier, who works part time in a furniture store. "You know you may never get another chance; it can all be taken away too quickly... . There's never a day when you say 'it's a great day' or 'it's great to be alive.' I haven't had one of those.

"It just affects your whole life... . It's a daily event; it has not gone away. I just find it amazing that a year later it's not all that better."

She has flown three times since the accident, and says she couldn't have made the trips without taking sedatives. Sirens or squealing brakes unnerve her. She turns her face from the TV any time a disaster report comes on. She forgets things, writes them down and forgets them again.

"Who do you go on vacations with?" she asks.

3:15 p.m. one year ago, the chicken-finger snack was being served on United Flight 232, 37,000 feet above northeast Iowa, when the tail engine exploded. The plane rocked, banked to the right and began to fall.

Shrapnel from the engine had sliced through the jet's control lines. Precious hydraulic fluid drained away in two minutes, leaving the crew with no control over the plane's steering system. But by varying the thrust to the jet's two remaining engines, Capt. Al C. Haynes and his crew were able to keep the plane flying the 70 miles to Sioux City's Gateway Airport.

The crash came with the warning: "Brace, brace, brace."

Joseph Trombello, a Chicago auditor, clutched the seat in front of him as the other passengers tucked heads into laps, grabbed ankles and held children on the floor. He watched it all from his upright position: "You ever try to get into a brace position in coach?"

Looking across Row 18 to the other side of the plane, over knobs of ducked heads, Trombello saw the ground rise up as the plane dipped to the right. He is sure he saw the wing catch the ground the moment before the jet cartwheeled into a fireball and split apart.

"I felt like a shoe in the dryer," he recalls.

Then he was upside down, hanging from his seat, his glasses gone, smoke in his eyes, nose and mouth. In the dark, he heard moans. All he could think to do was to crawl through the smoke and debris toward a hazy patch of light into the cornfield.

Two explosions followed quickly after his exit; he was almost knocked down by a passenger running back into the burning plane.

"I wish I had been able, capable, of helping somebody. I wish I had taken time out to try to help someone," he says. "It might not have done any good, but it would have eased my conscience. Just trying to get out was the main concern." Twice, he says, he thought he was going to die. "The smoke and fire was going to get me."

He had a dim vision off to the side of a mangled heap that had once been an old woman. "Keep your head straight," he recalls someone telling him. "You don't want to see that."

Finally, walking through the tall corn, he came upon an Air National Guard trooper. "You're going the wrong way," the guardsman said.

"What's the right way?" Trombello asked.

Looking for clues to help the survivors of that cornfield, researchers have gone to the battlefield. In West Haven, Conn., at the Department of Veterans' Affairs' National Center for Post-Traumatic Stress Disorder, Dennis Charney gives two groups of volunteers a small dose of a drug that stimulates adrenaline in the brain. In one group nothing much happens. In the second one, composed of veterans who served in Vietnam 20 years ago, the dose unleashes a torrent of emotion, nervousness and even flashbacks.

Charney says the experiments seem to show that brain chemistry is altered by severe trauma; those subject to the terror of combat, and perhaps airplane disasters too, develop a heightened response to stress, to noises, sights, smells -- anything that reminds them of their original experience.

Rescue workers and loved ones can also suffer from stress disorders.

Neil Mahoney, a clinical psychologist in Chicago, says that family members of those killed sometimes have it even rougher than those who actually went through the ordeal and survived. "For them the clock hasn't moved at all. Nothing has been resolved for them," Mahoney says. "They lost a loved one. They don't know who is responsible. The wound is still open."

When Trombello went to bed on a recent Sunday, he set his alarm for 4 a.m. for an early business trip. He woke up three hours early, filled with dread at the thought of flying. "The fear is always there," he says. "It doesn't get any better."

Before last summer, on long flights Trombello used to linger around the back of the plane, stretching his legs, shooting the breeze. Now he only leaves his seat when he has to. Although it seldom works, he tries to focus his mind on something, anything. He pays rapt attention to the flight attendant's safety instructions. He flips through magazines without reading. He doesn't eat or drink in the air anymore, either.

"I don't want to be distracted," he says. "I just listen for things."

"I just can't control it," he adds. "My heart beats so fast, one of these days I'm going to have a heart attack."

Life for Trombello on the ground is "pretty decent," he says, but he spends 75 percent of his work time in the air. With the Midwest and New England to roam as an auditor for a hotel chain, he doesn't have a lot of choice. He's not ready to ditch a job he's had for 11 years.

"Most people feel that time will heal things. I haven't found that. For me personally, it hasn't gotten any better. I didn't think it would take so long," he says.

Trombello goes to monthly meetings of a Chicago support group for Flight 232 survivors and their families, where they talk and cry about feelings that only their fellow victims can understand. They've watched the videotape of the crash. Some were upset, others viewed the accident frame-by-frame.

The relatives of those who died on the plane ask a lot of questions; they want to know if their loved ones suffered.

"It's hard to sit there," Trombello says, "and not feel a sense of guilt."

Priest, a 24-year-old communications director with a Northglenn, Colo., data processing company, also goes to monthly meetings of a support group. Most of the two dozen members were planning to attend today's reunion in Sioux City. Just about all were planning to drive -- nearly half a day's haul from Denver.

Priest is one of the few who has flown since the crash -- three times exactly, the Denver-Chicago route each time. "Next to the crash, it's the worst thing I've ever put myself through," he says of those flights. "It was a mistake... . I had this attitude that I didn't want this thing to beat me, but it did."

He says, "I hate to be up there. I know how out of control I am. There is nothing I can do. I can't say, 'Whoa, let me get out and fix the engine.' "

One small source of comfort is a teddy bear a flight attendant gave him. The stuffed animal sports a pair of United pilot's wings and a pin, a gift from 232 Flight Engineer Dudley J. Dvorak, that proclaims: "I feel like I'm a miracle."

For Priest, life has been made easier by a new-found faith in people, a legacy of the community outpouring in Sioux City last year, where citizens opened their homes to survivors and even bought pacifiers for infants who had lost theirs.

But his religious faith was also tested and found wanting. The memory of what a DC-10 smashing into a runway at 220 mph with 5,200 gallons of jet fuel can do to a child's body will not go away.

"The aftermath of the plane crash is with me every day," he says. "The 112 who died are with me every day... . The cruel reality of the whole thing is that the world keeps turning. We're still here. What do we do?"