In a recent fight in St Hilda's Secondary School, the vice-principal was wrong to say that because the man in the video was not a teacher, it was right for him not to intervene in the fight (Man in viral fight video not a teacher: School; Sept 15).

The least he could have done was call for help or send someone to get help, as a public-spirited person.

The adult voice is a powerful weapon. The man could have let the students know that they would get in trouble.

Schools need to teach students to resolve conflicts peacefully. Looking out for warning signs, such as social withdrawal, excessive feelings of isolation or excessive feelings of rejection, can help to prevent a fight from erupting.

Schools should watch out for patterns of impulsive, intimidating and bullying behaviour.

Students who display any of these traits should be counselled.

Francis Cheng