"Almost everyone is in denial that this could happen to such a good friend," said student Chris Huitink.
Lynch was running with three of his teammates to practice at about 3:30 p.m. Tuesday when he was struck by an SUV while crossing Woodman Avenue.
Sherman Oaks resident Larry Solomon was waiting in traffic when the teenager was hit. He said he and other witnesses rushed to the boy's side, but Lynch was unresponsive moments after he stepped off the curb and into the street. He was declared dead at the scene.
"He cleared her lane. He saw her coming, she was in the first lane, if she had just stayed where she was at, she would have passed behind him," Solomon said.
Parents like Cindy Lelles stopped by the campus to leave flowers in memory of Lynch.
"They're like brothers, they're going to be devastated, all of them," she said through tears.
Police said the 18-year-old driver, who is not a Notre Dame student, did not yield as she was traveling northbound on Woodman Avenue, and after she hit Lynch, she did not stop immediately. She stopped about a mile later when she spotted officers responding to an unrelated call.
She was detained, and then later arrested for felony hit and run. She was identified as Moran Biton of Sherman Oaks. Police do not believe she was driving under the influence.
Biton made bail just after midnight and will be arraigned in a Van Nuys courtroom on Nov. 9.
Student Ryan Nelson described Lynch as "a really nice guy."
"He was always there for his friends. He was always helping me out when I didn't get Spanish. If this was going to happen to anyone, it shouldn't have been him," Nelson said.