The moment teacher gets KNOCKED OUT during brutal student melee

A raucous brawl among female students at a Pennsylvania high school left eight teachers injured on Wednesday.
A substitute teacher at Cheltenham High School in a suburb of Philadelphia called Wyncote suffered a concussion while trying to break up a brawl involving four students, two of whom are sisters, at around 7.30am Eastern on Wednesday.
All four students involved in the altercation were arrested on charges including assault and reckless endangerment, according to the smoking gun.
Only one student, Amber Lewis, 18, was charged as an adult, while the rest were charged as juveniles.
The footage was captured by William Bastone.
A student in a light grey top and dark track pants is first seen hitting a student in a tie-dyed shirt.
Then another student in red and black flannel shirt comes in from the right to attack the girl in the tie-dye.
Almost at the same time, a student in a slighter darker grey shirt and white pants comes running across the hall over to the fight and turns her aggression on the student in the red flannel shirt.
The two separate fights continue for a few moments before an adult can be seen trying to break up at least one of the grappling sessions.
The next frames show the student in the tie-dyed shirt as she falls to the ground and the student in the light grey top and dark pants grabs her by the hair as she punches her in the face.
At this point other adults, and possibly another student, try to calm the chaos, as the other punching match continues down the hall.
From the ground, the student in the tie-dyed shirt is able to rip the light grey top into tatters while it's still on the other student's body.
She then makes it to her feet and bowls over a teacher trying to keep the two separated.
In the furor, a teacher with short, light hair is thrown to the ground, where she stays for the several seconds remaining in the video.
The last shots in the clip show the student in the tie-dyed shirt chasing down the hall after the student in the light grey top with her fists flying in the air as a man comes into view and he and other adults move toward the teacher on the ground.
'I wish to clearly state that the district will not tolerate fighting. I also wish to clearly state that we will not tolerate the filming of fights,' Cheltenham High School's principal, Ray McFall wrote in a letter to parents on Wednesday.
'Both behaviors are beneath us and reflect poorly on our larger population,' he said. The full text of his letter can be read in a photo of the text below.
Lewis remains in custody in the Montgomery County jail in lieu of a $10,000 bond.