When 16-year-old Jennifer Parnell made her New Year's Eve plans, her parents relaxed because their daughter, a cheerleader at Oakton High, would be celebrating at a friend's house and then spending the night.

It was on her way back home the next morning that Parnell was killed in a two-car crash on a busy Reston road that left five other teenagers injured, three of them seriously.

"You don't expect this to happen at noon with the sun up," Jennifer's father, James Parnell, said yesterday. "I don't know what happened to cause the accident. All I know is she never got home."

Two passengers in Parnell's car, 17-year-old Patrick Hagerty, of Herndon, and 16-year-old Zachery Williams, of Reston, remained in critical condition with serious head injuries yesterday at Inova Fairfax Hospital, according to police and a hospital spokeswoman. Both are students at Oakton.

A third passenger, Jonathan Francis, 16, of Herndon, was treated for minor injuries, police said.

The driver of the station wagon that collided with Parnell's car, David Shiroma, 19, of Falls Church, was treated for minor injuries, police said. His passenger, William Guiterrez, 16, of Chantilly, suffered a fractured pelvis and was taken to Columbia Reston Hospital.

Parnell, who was a junior, was driving with the three friends at Lawyers Road and Myrtle Lane in Reston when she pulled in front of an oncoming station wagon, police said.

Police said that the accident investigation is continuing but that speed was not a factor. Neighbors who live near the crash site said yesterday they have long worried about the high volume of traffic on the winding four-lane road and the difficulties motorists have at the Myrtle Lane intersection, where there is no traffic signal.

There were three accidents at the intersection in 1999, according to police.

"We always knew there's going to be another accident there. It was just a matter of when," said Sandra Schmer, who lives on Myrtle. "They need to do something."

Her husband, Robert Schmer, said he heard the crash and rushed to help. "I didn't hear any brakes," he said. "I just heard a crash."

Later, when emergency crews were working, he walked his two sons, ages 10 and 13, to the scene to show them the danger. Even though the boys have a few years before they'll be driving, "I want to make sure they understand," Schmer said.

Police said Saturday's crash occurred about 11:15 a.m. when Parnell, who was driving north on Myrtle, attempted to make a left turn onto busy Lawyers Road.

James Parnell said yesterday that his daughter, who got her driver's license in May, had spent hours behind the wheel. "I'm one of those parents who insisted she had a lot of driving time," Parnell said. "She had a lot of miles under her belt."

Parnell said his daughter spent Friday relaxing with the family and then headed off that evening with several friends. Some of those same teenagers came back to the Parnell house Saturday evening to mourn their friend.

"She had so many friends I couldn't keep up," James Parnell said.

Tara McMahon, 17, a classmate of Jennifer Parnell's, stopped at the accident site yesterday to remember her friend and add a bouquet of flowers to a growing memorial.

"She was friends with everyone in the school," McMahon said. "She was just carefree and friendly with everybody.

"We were supposed to hang out Saturday," McMahon said. "She said, 'I'll call you,' but she didn't call. When I called, her sister told me."

CAPTION: Jennifer Parnell was killed on a busy Reston road while driving home from a New Year's sleepover.