For three days, a woman lay unconscious in Fairfax Hospital, her face so badly disfigured that relatives did not recognize her. For three days, one of those at her bedside pushed aside his doubts about the woman's real identity, afraid it would mean his sister was dead.

"I knew it wasn't my sister," Rick Klingebiel, 26, said yesterday, following the startling revelation Tuesday night that his sister, 18-year-old Alana Klingebiel, had been among four persons who died in a car crash near Annandale early Sunday.

"Her [Alana's] hands were very much smaller. Her [the survivor's] legs were bigger. Her [the survivor's] eyes looked green. Alana's were blue. Just little things," Klingebiel said. "But the hope was there. And the prayers. I just didn't have the heart to tell anybody."

The mistaken identity was discovered Tuesday night when a Fairfax County police officer investigating the crash went to the hospital. "Alana?" he asked the woman who had just regained consciousness. "I'm not Alana," she whispered. "I'm Cathy Storey."

Cathy Storey, 21, had been identified earlier by family members as one of those killed in the accident. Her family had agreed to have the body they believed to be hers cremated, and her ashes were to have been buried today inside the coffin of her fiance, who died in the accident. Because of the mixup, the body of Alana Klingebiel was cremated instead.

"How can you be angry?" Rick Klingebiel sighed. "We're just disappointed. I wasn't even able to go to her funeral."

County police officials, attempting to explain the confusion, said yesterday that Fairfax Hospital was handling survivors of separate multiple-injury car crash at the same time early Sunday morning, hampering efforts to determine immediately who was involved.

Police said one survivor of the Storey-Klingebiel accident mumbled the name of Janet Thorpe "over and over again," leading authorities to believe that Thorpe might be the unidentified dead woman. Thorpe is related by marriage to one of the survivors.

Police contacted Thorpe's parents, who viewed the disfigured body in Fairfax Hospital's morgue and came away believing their daughter was dead. An hour later, Janet Thorpe walked through her parents' door unaware of the tragedy.

"We all cried together," said her mother, Mary, of their reunion that morning. "I was in a state of shock."

Storey's relatives would not comment yesterday on the mixup involving their daughter. At the Fairfax home of Lawrence O'brien, Storey's fiance who was killed in the crash, family members said they greeted the news that Storey was alive with tearful emotion.

"It was unbelievable," said O'Brien's 31-year-old brother, Kevin. "We were crying in disbelief, crying for joy. We all had our arms around each other and the next thing we knew, we were praying -- praying out of gladness for Cathy and sorrow for the Klingebiels."

Police yesterday brushed aside criticism from relatives and some area officials that procedures used to identify the crash victims were inadequate. "There were peculiar doubts and uneasiness" on the part of the parents involved, said Fairfax police Maj. Thad Hartman. Nonetheless, they all gave positive identifications, he said.

"The onus is certainly with the parents," Hartman said.

"It's not enough," said Kevin O'Brien, who with his father identified his brother's body. "Visual identification just isn't enough. Already when you go down there, you're thinking, 'That's my brother in there.' You want to get it over as fast as possible. But something more than speed is important."

Alana Klingebiel's death brought to three the number of teen-agers killed in a car driven that night by 19-year-old Jonathan P. Reinemer. Also killed were Deborah Rogers, 17, and Wallace Simpson Jr., 18. The fourth victim, O'Brien, was the driver of the second car involved in the crash.

Reinemer, listed in satisfactory condition at Fairfax Hospital with a broken pelvis, has refused to talk with reporters. The cause of the accident is under investigation.

Police have refused to release details of events leading to the violent collision in front of stately Walnut Hills mansion on a curve on Annandale Road. Witnesses to the crash, however, reportedly have said that Reinemer, Klingebiel, Rogers and Simpson had been at an open-air party in a vacant lot near the Beltway.

Police will say only that excessive speed was a factor in the crash and that at least one other car was involved. Witnesses from a third car have been interviewed by police, authorities said yesterday.

O'Brien, Storey and a friend, Michael Bacon, were returning at the time from the Brickskeller, a pub located near Dupont Circle in the District. O'Brien was driving southbound in his Mazda when Reinemer's Chevrolet Nova, described by police as out-of-control, collided with him.

Both cars tumbled down a 12-foot embankment. Tearing out a 25-foot-long section of white rail fence, the two cars came to rest 100 feet from a small pond lined with serenely drooping willow trees.

O'Brien apparently died instantly, police speculated. The crash was of such force that his shoes were left imbedded in the car's floorboards.

"He was such a happy person," said Kevin O'Shaughnessy, O'Brien's supervisor at a furniture store in Merrifield and classmate at George Mason University. "In the two years I knew him, I think I only saw him angry once."

At the last minute Saturday night, O'Shaughnessy had declined O'Brien's invitation to join them at the Brickskeller.

This week spectators have completed for parking spaces along the sweeping curve to view the accident site. The disconsolate property manager, David Refshahl, assessed the damage.

"In the six years I've been here, probably 24 people have gone through this fence," mused Refsahl. "I don't know what it is. They just lose it. I guess they don't realize how bad that turn is up there. But these kids, they all lived around here. They should have known."