If you were one of these security guards, would you have stepped in to help?

Yes I would have tried to stop it immediately. It makes me sick when I see what the security guards didn't do. I don't care what their job description says they should do. Shouldn't human compion come first? They said that the girl had already told them that she was scared these other kids were going to jump her. If I were her parents I wouldn't stop until they were all fired.