The cell phone video was taken by students at a middle school in Tacoma. It appears to show a 13-year-old boy being dragged around the classroom, even having a sock stuffed in his mouth.
Students are seen writing on his feet, holding a pillow over his face and covering him with chairs.
The boy's parents are outraged that no one -- including the teacher -- tried to help their son.
"He said he wanted to kill himself," said mother Karla Kinney. "The kids had blamed him for this popular teacher and the suspension that he received."
Teacher John Rossi avoided getting fired by accepting a 10-day suspension but was reassigned to another school.
Rossi said he thought the youngsters were "horsing around."
Police are now investigating.