The heartbreak of bullying

A seventh grader in our community committed suicide last weekend. Why? Bullying. Even typing the word is ugly. Although we didn't know the girl or her family, I still feel a strong sense of heartbreak.  I look at my children and the mama bear in me comes out.
I "get" that kids can be cruel. That teasing and being picked on happens. I'm not saying it's right, just acknowledging. But, actions and behavior that are so horrific as to drive a beautiful young woman with her whole life ahead of her to feel that this is the only way to escape?? What happens that kids think that it's ok to cause such pain to others? My information is not from the source, but I've been told that her food was spit in, that even away from school, she had no relief because the bullies were texting her, talking about her on social media. Her parents thought that the issue had been addressed and was under control.
It makes me literally sick to my stomach. As a parent to two children who will likely always be perceived as "different," I am concerned for them. This girl who felt like she had no other options wasn't different. She was smart, active in sports, not socially disadvantaged. Looking at her picture, she was very pretty. If those things weren't enough to "protect" her from bullying, how do I keep my children safe? Mark and I have agreed that we need to make sure that our kids feel comfortable telling us (or someone) if this is happening to them (or anyone they know). Just as important will be teaching them the value of life in any form and that bullying another is unacceptable. I'm thankful that they are young enough and sheltered enough to not be exposed to this type of behavior yet. But, the time will likely come.
In the meantime, I share the shock, anger, sadness of many others about the senseless tragedy.  Although I can not imagine what they are feeling, I look at my children and know that to lose one of them in this way would be heartbreaking beyond words.  My prayers go out to the friends and family. May God meet them in those darkest moments and provide them with peace which passes understanding.