Disturbing video has surfaced showing the chaotic confrontation that preceded the death of a 12-year-old girl who was allegedly struck in the head with a metal water bottle while trying to protect her younger sister from bullies at school. The footage, recently obtained by local media, shows a group of students arguing and pushing in a hallway at Reseda Charter High School moments before the violent incident that would leave sixth-grader Khimberly Zavaleta Chuquipa with a fatal head injury.Chuquipa stepped