that happened when I worked in school police for a K-12 district nearly 40 years ago...
high school rival players got into a fight on the field, then both teams and their fans got involved...musta been close to 800 people pushing, shoving, kicking, throwing punches...players were swinging their helmets at anybody wearing opposite colors, peeps grabbed the sideline markers and used them as spears and clubs...
two school police officers and I were overwhelmed....that was a pretty scary 5-10 minutes...luckily there were enough calm parents, teachers and coaches to help restore order, before dozens of city police arrived...we separated the two groups onto opposite sides of the field, and told one side to leave while monitoring the other...