One recent night, Jerry Edgerton received the telephone call that every parent dreads. Fairfax Hospital was calling. There was a serious accident. He must come right away.

In a hospital consultation room, with "too much furniture" and water cups that tasted "like soap," the nervous father learned the terrible news about his only daughter. She had left home earlier for a party with a kiss, a hug and her current hip farewell, "Later days."

There would be none.

Since the night of July 3, a McLean community among the gently sloping hills of Fairfax County has been numbly coping with the death of 17-year-old Amy Edgerton, a popular Langley High School honors graduate.

She and three other recent graduates were thrown from a black Toyota truck that rolled, then flipped upside down, in what police describe as an alcohol-related accident at Lewinsville and Windy Hill roads.

Edgerton died soon afterward. Brigid Kerrigan, a friend who was behind the wheel, clung to life. Her condition yesterday was listed as fair by Fairfax Hospital. Two male teen-agers were bruised but were able to walk away.

In the exhilarating milestone year of graduation, the accident has splintered forever a group of teen-agers whose friendship, classmates say, was cemented during the sun-washed days of "Beach Week" in Ocean City, Md.

"When you stay with someone at Beach Week, you get to be good friends. Amy told me that was the best week of her life," said a 17-year-old schoolmate, Kim O'Bryan.

Amy Edgerton's death has had a profound impact on this community, parents and friends say. If death could strike a girl with so much compassion and zest for life, they say, it brings home the realization that it could happen to anyone, anytime.

"She is just the kind of girl that you can't imagine, at 17, being snuffed out," said Janice Martin, one of Edgerton's former teachers at Langley High School.

The tragedy has added to the painful pall already cast over Langley, a school that has been hit hard by the deaths of four other students in the past three years.

"It seems like every six months something has happened," said Langley Principal James Manning. "It's very difficult to deal with . . . . You have to pray a lot."

On the night of the accident, a crowd of teen-agers estimated by police and witnesses at 50 to 75, gathered at Fairfax Hospital to find out what had happened. Police were called in to calm them down.

Three days later, more than 600 people turned out for a memorial service for Amy Edgerton held in a Colonial-style Episcopal church on Georgetown Pike. The parking lot was so jammed with cars that many who attended were forced to wait an hour to get out, church officials said.

But now, even as grieving residents turn to one another for consolation, the contradictions about what happened have set off a ripple of rumors in this affluent community.

Police say they believe that all the teen-agers were drinking alcohol, a factor that contributed to the accident on a clear summer night. The claim is vigorously denied by some teen-agers and parents.

"There are three things that are killing kids in this county," said Capt. Ronald Miner, Fairfax County police traffic division commander. "Speed, not wearing seat belts, and alcohol. I don't think speed was a factor, but the other two were."

A flurry of telephone calls had firmed the teen-agers' plans for that night. Edgerton was picked up at her home after 9 p.m. by a friend, Suzie Purcell. They went to a schoolmate's barbecue, where they met up with three friends, Brigid Kerrigan, Rob Holcombe and Steve Lock, whom Edgerton decided to accompany to another party.

They never made it.

Scattered around the truck and broken glass were two coolers, cases and loose cans of beer, a white flip-flop sandal, a blue hat and a Styrofoam holder containing an opened can of beer, police photos show.

While the causes of the accident are still under investigation, police say they believe that the Toyota flipped over because the driver oversteered. Police are trying to determine why the wheel was jerked.

Some parents and witnesses say they are convinced that the intersection of Lewinsville and Windy Hill is dangerous. The stretch opens from two lanes to four, consisting of two left-turn lanes, one through lane and a right-turn-only lane.

Miner, however, said the intersection is "a safe road if you are doing what you are supposed to be doing."

Witnesses told police that a blue car traveling to the right of the truck on Lewinsville cut in front of the truck driven by Kerrigan, who swerved to avoid it.

Holcombe, the Toyota's owner, who was sitting in the front passenger side, said, "The blue car took off really fast like he was racing . . . . As four lanes went into one, he cut in front of us."

Police said they are treating the crash as a single-car accident but are looking for a second car.

Some witnesses and parents insist that the teens were not drinking the alcohol in the truck but were taking it to the party.

Miner, however, said he believes the teen-agers were drinking, based on evidence at the scene and statements from witnesses. Whether the youths were legally drunk will be determined by the results of tests being conducted by a lab in Richmond, he said. He would not say which of the teens were tested and what kinds of tests were conducted.

For many of the people who knew the four teen-agers, sorting out the events of that night is making it even more difficult to cope.

"The very awful things have been the rumors and the innuendoes floating around," said Kathleen Lock, the mother of 17-year-old Steve Lock, who was in the back seat of the Toyota. "From my point of view, it can never be over for any of those children involved."

The scent of fresh flower arrangements was heavy last week in the Edgerton house, where the family has received a stream of sympathizers. Even in their mourning, Jerry and Barbara Edgerton were eager to talk about their daughter's life.

The father pointed out the photographs that chronicled his daughter's life in four montages, pieced together by Amy's friends. There was Amy being "kidnaped" on her birthday. There again was Amy in a red prom dress careening on a skateboard. Here was Amy grimacing as she poured motor oil into the 1959 Morris Minor given to her by her father. Amy in cap and gown with best friends on graduation night. Smiling pictures of Amy as a toddler.

"You can see some of the spirit in this gal," a red-eyed Jerry Edgerton said proudly.

His daughter had a black belt in karate, but she also had a penchant for trendy clothes and such progressive new wave groups as Echo and the Bunnymen and the Cure.

She planned to study systems engineering at the University of Virginia, a field she became interested in because of her father, an engineer who runs a division of McDonnell Douglas in Tysons Corner. She had been accepted by nine colleges. Her father pointed to the college letters and applications piled high under her bedroom window.

"We really had something special, didn't we, Jerry?" Amy's mother said quietly to her husband, her hands clasped together.

"Absolutely," the father said.