A 24-year-old Laurel man was killed early yesterday morning on Interstate 66 in Fairfax County after he got into an argument over a traffic altercation, left his car and was chased into the path of an oncoming truck, police said.

Cesar A. Flores was struck by a bakery truck about 3:45 a.m. after he and a friend had stopped their car on the shoulder of the highway to confront five men in another vehicle, Virginia State Police spokeswoman Lucy Caldwell said.

Witnesses told police that one of the five men drew a knife and chased Flores into the westbound lanes of I-66 near the Dulles Access Road, Caldwell said.

"It started out as some kind of road rage altercation and ended in one death," she said. She said the five men drove away just before police arrived and are being sought for questioning.

The fight began with the two vehicles, but at least six other cars--containing friends of Flores's or the other group--stopped to take part in the confrontation, Caldwell said. Flores, a salesman at Stohlman Mitsubishi Motors in Tysons Corner, was taken to Inova Fairfax Hospital with massive head and internal injuries. He was pronounced dead there at 5:40 a.m., a hospital spokeswoman said.

His extended family, who gathered yesterday afternoon at his parents' apartment near Tysons Corner, remembered him as an energetic, fun-loving friend.

"He was a family guy 100 percent," said his mother, Ana Flores, 46. "If he wanted to do something, he would do it with us. If he wanted to do something with his friends, he would bring them all over to the house."

Flores's roommate, John Chang, also a salesman at the Mitsubishi dealership, said Flores and his younger brother Mario had left for a night out in the District about 11 p.m. Friday. Cesar Flores had celebrated his 24th birthday a few days earlier, Chang said.

Flores and his friend, whose name was not released, were riding in a white BMW and the five men were in a black Jeep Wrangler when the incident on westbound I-66 occurred, Caldwell said. She said the BMW, which was being driven by Flores's friend, may have cut off the Jeep and then slowed, angering the Jeep's driver.

At that point, both vehicles pulled over to the side of the road. Mario Flores, who was driving another car, then stopped, as did other vehicles.

"The violence escalated when one of the people in the black Jeep crashed out the rear window of the BMW," Caldwell said.

The man who drew the knife was one of several people who chased Flores into the path of the oncoming truck, Caldwell said. She said the driver of the bakery truck does not face charges.

Caldwell said several passing motorists called police to report the fight as it escalated. As a trooper arrived, several vehicles drove off, including the Jeep and the BMW, she said. She said the driver of the BMW apparently left to chase the Jeep.

The man wielding the knife apparently fled on foot and escaped in the confusion, Caldwell said. Witnesses told police he was about 6 feet 3 inches tall and was not wearing a shirt.

Investigators are trying to determine the sequence of events and locate key witnesses, Caldwell said. "We still need a lot of information before there are charges," she said. "There are a lot of open questions."

Flores, one of three children and a graduate of George C. Marshall High School, had moved out of his parents' apartment a month ago to live with Chang. In June, Flores had purchased a red Mitsubishi Eclipse, "the car of his dreams," his mother said.

"Probably the past two or three weeks of his life he seemed to be doing well," she said. "He was happy." He was earning a decent living at his new job and hoped to save enough to return to Marymount College, where he needed to complete one more year of study to earn a computer science degree.

"He was just an all-around good kid," said Paul Tchong, general sales manager at Stohlman Mitsubishi, who hired Flores about four months ago. "He was very friendly, a very good worker and he presented himself very well."