This really is terrible to see. And the worst part is that it's something more common than most would want to admit. In grade 10 i had a teacher who was always the target of most students. There were a couple of times we (and i share blame in this)got her crying and leaving the classroom. We all thought we were funny.

I took another class with her in OAC/Grade 13 (Ontario used to have an extra year). Only this time, most of the troubled kids had already left the school. So the class was smooth, and she didn't take this chance to punish me. She passed me with an 80%, which was a confidence boost i needed at the time (things had been going south for me since Grade 10, the irony). I felt so ashamed. I apologized for my role in tormenting this poor woman. She forgave me.