the serial killer

a serial killer has escaped prison and he went to a high school with guns and knives. He kills other students and teachers, some of the students died and some were hiding in the restroom the others were hurt but still alive. The persons who were hiding 3 girls, 4 boys and 2 teachers, the some of the students were crying and the teachers were calling the police but there was no signal they tried to escape but the killer was guarding the door, there was a small window in the restroom but they cant fit