Kimberly Quintanilla said the boy whose gun discharged - and wounded two students - entered her classroom after the shooting, but was not threatening.
For Quintanilla, the incident started with an announcement over Gardena High School's loudspeaker system, barely two hours into the first day of school after the three-day Martin Luther King, Jr. weekend.
Administrators ordered a campus-wide lockdown, asking teachers to keep their students inside their classrooms.
Quintanilla, 15, was in her choir class at the time. “During the lockdown, they ordered all the teachers – whatever kid was out there – to just let them in."
Quintanilla said she didn’t recognize the boy who walked through her class into an adjacent office and storage room. She could see him inside through the glass, but didn’t think much of it.
At some point, the tenth grader said, she went into that same room to use a cellular phone to call her parents and tell them she was OK.
”The back room has the best reception in that area," she said. "So I went back there with two other friends of mine who are ninth graders who go to the same choir class."
"He was in there and we didn’t even know that it was him, until later when they told us.”
She said her teacher told them that the boy was the one whose gun discharged earlier in another classroom, hitting two students.
Quintanilla said she saw her teacher speaking with him earlier, then talking to police officers who had knocked on the door.
“All of a sudden they grab him and then they yank him out and they throw him to the floor and they search him," she said. "Then everyone freaks."
Police ordered the rest of the students to come out of the classroom one by one, without their backpacks.
"Some of the students were crying, they were scared."
Quintanilla said she wasn't scared.
"I was calm," she said. "You have to be calm in those situations. You don’t know what’s going to happen.”
With that, Quintanilla shrugged her shoulders and left Gardena High School with her father.