A 15-year-old student opened fire at a private school in the northern Mexican city of Monterrey on Wednesday, shooting a teacher and two other students in the head before killing himself. Another student suffered lesser injuries in the shootings, which were captured on a chilling video posted to social media.

Nuevo Leon state Gov. Jaime Rodriguez said the shooter died at a hospital and that his three victims with head wounds were “fighting between life and death.” The boy wounded in the arm was out of danger.