CNN — When the shooting started at her high school near Portland, Oregon, early Tuesday, student Jaimie Infante didn’t recognize the sound of a gunshot.She thought maybe somebody had dropped a book.In reality, a lone gunman had opened fire at the school, killing one student and forcing others to flee.An assistant principal told students to go into lockdown mode. Student describes the Oregon shooting Police: Oregon school shooter dead Student’s parent: We just panickedPhotos: Shooting at Oregon high school”At the end he said: ‘This is not a drill,'” Infante told CNN.A teacher, who suffered non-life-threatening injuries, was treated at the scene. The suspected gunman is dead.According to multiple law enforcement officials, the shooter was a student at the school. The gunman appears to have died from a self-inflicted wound, the sources told CNN.Speaking to reporters, Troutdale Police Department Chief Scott Anderson said he could not confirm how the shooter died. He identified the student killed as 14-year-old Emilio Hoffman, a freshman.