Police say a 16-year-old boy who they say was”flashing two knives around” rampaged through the hallways of Franklin Regional High School.Four high school students are in critical condition at hospitals near Pittsburgh after being stabbed at their school Wednesday morning. Nineteen students and a school police officer who eventually subdued the boy were injured. Police says someone pulled a fire alarm during the incident and that likely helped students get to safety faster than they would have otherwise.