A small fire set in a classroom sparked another teacher assault at the West Philadelphia High School today.

The injured teacher was the eighth in two weeks to be assaulted at the school.

After a trash fire was set in a classroom, students were let outside to 48th street. Chaos erupted.

"Three students assaulted a 53-year-old teacher, punching him the face and knocking him to the ground," said police Capt. Michael Sinclair.

The teacher, a long-term substitute whose name was not released, was taken to the Hospital of the University of Pennsylvania. He suffered injuries to the face and jaw.

Students were taken inside but many chosed to skip school and left for the day.