It's a great shame that this happened because in so many ways it was so uplifting. It puts a permanent blemish on what happened here. I think the kids made a mistake. They did not intend for this to happen.
I can't give you an explanation. I guess they were kids blowing off some steam and it got out of hand. In this case, my sense is that it was a mistake. These kids did not intend to do what happened.