Eloi Vasquez, a 19-year-old freshman, died early Saturday on eastbound Interstate 10 about a mile from USC after he was seen leaving a fraternity party, the California Highway Patrol said.
A woman said a man ran in front of her and she was unable to avoid hitting him, said Officer Edgar Figueroa, a CHP spokesman. The man was struck just east of Vermont Avenue. The investigation is ongoing.
Vasquez was pronounced dead at the scene. He was not carrying identification, which set off a missing persons search until the coroner could identify him.
Coroner's officials had worked with the CHP and Los Angeles police, determining that the man struck on the freeway was likely Vasquez because of where he was found and his age, Figueroa said. Fingerprinting of the teenager did not yield any matches, he said.
Vasquez, who was on spring break in Los Angeles, had left the party to take a walk with no money and no wallet, family and police said.
His mother Wendy Margolin said he later called a friend, telling her he was lost and in trouble.
Figueroa did not know if Vasquez had alcohol or drugs in his system. Toxicology screens to detect substances usually take weeks to complete.
The family had offered a $100,000 reward for information about his whereabouts.
"Needless to say, we are heartbroken, we are devastated upon finding out this news," Wesley Mallette, associate athletic director at the Berkeley campus, said at a news conference.
"Eloi Vasquez was a wonderful young man, a fantastic student-athlete, dedicated and devoted to everything he did."
Vasquez's soccer teammates at Cal were informed of his death at a more than hour-long meeting.
Vasquez had traveled with other teammates to Southern California for the break and was supposed to return Monday for the start of second semester, coach Kevin Grimes said.
"Eloi was a wonderful teammate. He was very close to all of his players," Grimes said. "Our guys are grieving pretty hard right now."
Vasquez, a freshman midfielder, had hurt his knee during the year and was still recovering from surgery in December. He played in 12 games for Cal last season, recording three assists.
His coach described him as one of the hardest workers on the team who always stayed after practice. His youth soccer coaches would have to change the lock on the equipment shed to ensure he didn't work too hard on his own, Grimes said.
"When you combine his talent level with that mentality, it was a safe bet that he was headed to the MLS," Grimes said.
The school's athletic department remembered Vasquez on Twitter:
The Associated Press contributed to this report.
Police: Missing Cal Athlete Killed On Freeway
UC Berkeley assistant athletic director Wesley Mallette, soccer coach Kevin Grimes and teammate Alex Mangels remember Eloi Vasquez.