A 21-year-old Fairfax County woman believed killed along with three other younger Northern Virginians in a violent two-car collision early Sunday was found to be alive yesterday. She was misidentified after the crash.

A Falls Church woman, 18, listed among those hospitalized with serious injuries, is now listed as dead.

The error was discovered late yesterday when Fairfax County Police Officer T. D. Bender went to Fairfax Hospital to interview one of the three survivors, thought to be Alana Klingebiel, who regained consciousness yesterday.

When Bender addressed her as Alana, the young woman replied in a weak voice: "I'm not Alana. My name is Cathy," police reported last night.

Bender quickly summoned police officials and the Klingebiel family, asking the family to return to the hospital because "there might be a problem."

At the hospital, the family was led to the woman's bed in the intensive care unit and asked if the daughter had a slight deformity on her right foot. "They said no," a police spokeswoman said, and then a sister noticed that the person in the bed did not have pierced ears, as did Alana.

Further investigation showed that the woman in the bed was Cathy Storey, 21.

Alana Klingebiel, it developed, was among the dead; she had been cremated yesterday afternoon at the direction of the Storey family who thought she was their daughter.

Members of the Storey were called to the hospital after the Klingebiels left and were told that their daughter was alive.

Neither the Storey nor the Klingebiel families would comment on the misidentifications last night.

Officer Caroline Burns, the police spokeswoman, said both the dead woman and the living one had facial injuries that obscured their features and both families had made wrong identifications in the hours following the wreck.

"It's tragic; the wreck was that bad," Burns said.

The accident -- the worst in Fairfax in more than three years -- occurred about 2 a.m. Sunday on Annandale Road in Fairfax County. Two cars carrying young people returning from Saturday night outings collided and both hurtled down a 12-foot embankment on a curve near Gallows Road.

Cathy Storey was riding with two friends -- Lawrence O'Brien, 22, of Vienna, who was killed in the crash, and Michael Bacon, 21 of Fairfax, who is still listed in critical condition in Arlington Hospital.

Alana Klingebiel was in a car also occupied by Deborah Rogers, 17, of Vienna and Wallace Simpson Jr., 18, of Fairfax County -- both of whom were also killed -- and Jonathan P. Reinemer, 19, of Falls Church, hospitalized in stable condition at Fairfax Hospital.

Police said the northbound car carrying the four teen-agers, with Reinemer at the wheel, went out of control on the curve. It skidded sideways into the opposite lane, where it struck the car driven by O'Brien.

Both compact cars ran off the road, rolling over several times.

Storey, who was found to be alive yesterday, was planning to marry O'Brien, who worked at a furniture store in Merrifield, relatives said following the crash.