A school safety officer for the high school was alerted by staff that an assault had happened in one of the classrooms, police said.

Horne added that Maryvale has safety plans in place and a school safety officer (SSO) on campus during school hours. The difference between an SSO and a school resource officer (SRO) is that SROs are on school campuses full-time while SSOs are there one day a week, Horne said.

A student was stabbed to death and his alleged attacker was hospitalized after the two teen boys got into an argument inside an Arizona high school classroom just two weeks into the school year — sending students and their parents into panic mode.