This is beyond Heartbreaking...
Absolutely HORRIFIC and HEARTBREAKING. All Parents must be not only aware of but active, daily in demonstrating the Evils of Bullying. I truly hope that if bad or lack of parenting was involved or influenced, that they are punished. In fact, in severe instances such as this, I welcome a thorough investigation into the Parents, household environment, care, and more to determine if the Bullying child/children were influenced. Why? Because as a responsible parent myself, I know for a fact, that Children, especially this young, are absolutely influenced mostly by their parents and household environment and upbringing.