No one has been arrested for the shooting, and no suspect description is available. Police are unsure if the shooter was a student.
"She was happy all the time, she was a great person, and she didn't deserve it at all," said student Walker Getz.
Flowers, candles and balloons line the curb where Ross, a popular honors student and track-and-field athlete, was shot to death.
"She was a sweetheart. She was such a good girl," said neighbor Kathleen Longsinger.
Police said she had gone to the game with friends. When the game was over, Ross and her friends sat on a curb, perhaps to wait for a ride home. However, a few minutes later, a fight broke out a few feet away from them, someone pulled out a gun. Ross fell mortally wounded while two young men near by were hit but not seriously injured.
"I thought it was a joke. This isn't supposed to happen at Wilson," said student Cassy Schroeder.
Students held a pep rally in honor of Ross Monday evening.
"We used to walk by each other during passing period, and she always had the biggest smile. She just never came to school sad," said the victim's friend, Danielle Fudim.
"I left the game early, and she was standing here, and I saw her and I said goodbye, and I just didn't know it was the last goodbye," Fudim added.
Ross' parents, refugees from Cambodia's "killing fields," came to the school Monday and were talking to reporters about their daughter when a man identified as Wilson's vice principal, Tom Murphy, abruptly interrupted them, roughly pushing them inside school grounds. When he was told that it was a public sidewalk and that he shouldn't push people like that, his response was curt.
"So sue me," he said.
A school district spokesman later apologized for the vice principal's actions and said that Murphy was anxious to get Ross' parents inside for a school assembly.
Before the interruption, Ross' parents were about to make a plea to the public to help police.
"There were a lot of people out here who saw and heard things that would help law enforcement," said Chris Eftychiou of Long Beach Unified School District.
Los Angeles County Supervisor Don Knabe will ask the board to offer a $10,000 reward for information that leads to an arrest.
"Obviously there were a lot of kids, a lot of cell phones, whatever it may be, this is an opportunity just to do the right thing" said Knabe.
Police are hoping someone in the crowd has a picture or a cell phone video that might aid their investigation. Anyone with information is urged to call the Long Beach Police Department at (562) 570-7244.