Parents received a letter after extreme behavior at Doral Academy's Red Rock Elementary School campus earlier this week.
Witnesses say that parents cursed and threw rocks at staff because they were upset about a silent dismissal system that releases students in waves.
A staff member at the elementary school received a concussion from the incident Wednesday.
The principal's letter reads in part, "How are we supposed to teach our kids how to behave when the parents are behaving this way in front of them?"
