"It makes me feel terrible. It makes me feel like they just cut my guts out. I'm so saddened by it," said O'Brien. "I thought maybe they would show a little courage and stand up and do the right thing."
Last December, the Arcadia High School's boys cross country team led by coach O'Brien won their second national title in three years. In June, after 17 years with the district, O'Brien was fired.
"Why would you fire coach O'Brien? He's got two national records. He goes to state almost every year. What could he have possibly done wrong?" said student Isabelle Panza.
O'Brien says he believes he was fired for personal reasons. District officials say the coach was fired for vandalism; they say he drew an "X" on 72 athletic lockers. O'Brien says they were broken, and after a rash of thefts, he was trying to protect students because the district hadn't replaced them.
"They can look at it as vandalism. They can call it vandalism. They can warn me that that was an unprofessional thing, but I look at the other side of the coin which is they were negligent for a long time and not taking care of these kids," said O'Brien.
Eyewitness News has yet to hear comment from the school district on O'Brien's firing. Parents and students were hoping their support would have brought back a tough but inspiring coach.
"Coach O'Brien doesn't suffer fools. Could he learn to suffer fools a little bit more? Sure. As his employer, what I would do, is give him help," said parent Becky Pratt.
"Ninety-nine percent of these guys aren't born athletes. They have never thought about running in their lives before entering high school, and the coach just picked us out from wherever we came from, and he's made us into athletes. He's made people believe in themselves," said former student Esmond Wei.
Students and parents say they are going to begin the process of collecting signatures to recall three school board members.
O'Brien says he is considering legal action. He will be returning to the school next fall as a physical education teacher.