In the Olweus program, kids learn how to support victims when they see bullying. The program has shown how peers can often stop bullying more effectively than direct adult intervention. But kids are less likely to get involved in a situation like Klein’s because they don’t perceive adults as needing help, Raether said. Fewer kids may join in the bullying, but they are also less likely to intervene, she said.

A bus monitor should be trained to “set the tone to control the behavior,” Haber said. “The kids need to sit in their seats, be respectful, and know that there will be consequences when they get to school.”

The best way for the school to prevent future episodes of bullying probably starts with a conversation, experts agreed.

“There was some sort of breakdown there, and there needs to be an understanding of what happened,” Haber said. “There has to be some further discussion with that group … and the kids need to make retribution to the adult.”