Officials say a Gorton High School freshman pummeled a teacher in the school's hallway Monday afternoon while students recorded the incident on the cellphones.
During the incident, the student is shown throwing punches to teacher Ron Santavicca and applying a head-lock. Santavicca is the former coach of the Yorktown football team.
Yonkers police say no one was hurt during the fight.
Yonkers teacher's union head Pat Puleo says it's hard to decipher what prompted the incident.
"It could be that the child was in such a crisis situation that he became violent. Unfortunately, this teacher took the brunt of that violence," said Puleo.
Police have interviewed the student and the teacher to find the answers. They are also reviewing cellphone videos and surveillance footage.
The student has been suspended. No charges have been filed.