Dozens of bouquets of flowers -- white roses, pink carnations, daisies and a blue hydrangea -- piled up yesterday by the roadside where 16-year-old Vanessa Pean died early Sunday in a single-car crash.

A teenage boy paced around the spot in the bright afternoon sunshine, picking up pieces of her wrecked 2003 Land Rover and tossing them to the ground.

Annie Harris, 19, a friend who played soccer with Vanessa at the Potomac School in McLean, stood before the makeshift memorial, where someone had left a snapshot of Vanessa and someone else had scribbled a goodbye note.

"This kind of thing, it's too hard to understand," Harris said. "I can't even imagine the next couple of years. We're all supporting each other . . . but there's no answers."

The death of the teenager, a star athlete and excellent student, has hit hard in her Great Falls neighborhood and the close-knit community at Potomac School where Vanessa was a junior. At the school, students and staff gathered in the auditorium yesterday morning for silent prayer. A memorial service is set for Thursday. And hundreds of teenagers visited the Pean home Sunday and yesterday, sharing their grief with the family.

"Vanessa was just extremely energetic and outgoing and sensitive," said her sister, Monique Pean, 24. "She was so enthusiastic. The glass was always half-full."

Vanessa was a whirl of activity in the school's sports scene, playing soccer, lacrosse and basketball. She loved music, everything from rock to rap, and could rattle off statistics about professional soccer and football teams. And at 16, Vanessa had begun to set up a scholarship fund for children in her father's native country, Haiti.

Fairfax County police said Vanessa was driving on Beach Mill Road, a narrow two-lane stretch, near Walker Road about 12:10 a.m. Sunday when she ran off the road, striking two trees. Just before the crash, police said, she was driving westbound in the eastbound lane. She steered hard, crossing back into the correct lane, but veered up a roadside embankment.

Police said that speed was a factor in the crash and that Vanessa was not wearing a seat belt. Her sister said she had been driving home from a party where students had celebrated Potomac's football victory over Sidwell Friends School.

At the Pean home yesterday, snapshots of Vanessa covered the top of a baby grand piano. There was Vanessa as a little girl, dancing in a white dress, a silly shot of Vanessa in a banana costume and one of her as a young woman in an elegant gown.

Laura Bondel, 16, a friend and former classmate, plucked a photo from the pile. It was Vanessa, smiling broadly, one leg stretched high behind her back.

"That's when we went to camp with her," Bondel said, showing her sister, Elise, 17.

Sports were Vanessa's true passion. In addition to school sports, she was captain of a community soccer team, the Great Falls Strikers. She planned to become a doctor and practice sports medicine.

"She was so gifted athletically, I think she could have gone on in college and competed in her chosen sport," said Cas Blanchard, the girls' athletic director at Potomac. But as driven and hardworking as Vanessa was, Blanchard said, she was never too upset when things did not go the team's way.

"She really had the ability to keep it in perspective," Blanchard said.

In July, Vanessa, touched by the poverty she saw during trips to Haiti with her father, had begun setting up a scholarship fund at a private school in Port-au-Prince. Already, the school had let her know they welcomed the help.

"She knew she was so lucky to have a great education, and for only a few hundred dollars those children could have a remarkable education," said Gail Pean, Vanessa's mother.

Now her family plans to take over her work, setting up the foundation in her memory.

Potomac School freshmen Fiona Donovan, standing far left, Caroline Schmidt, standing next to her, and Ryan O'Shea, squatting, examine items placed at Vanessa's memorial.Vanessa Pean, 16, was a junior at the Potomac School in McLean.