JOHANNESBURG - Gauteng Education will probe why a teacher was armed while at school.
The Kagiso Secondary School teacher shot and killed a knife-wielding attacker after he stabbed his colleague.
The unknown assailant entered the school, demanding to speak to the principal.
Police investigations into the incident are also continuing.
"He actually strategically pushed his way after the gate was remotely open, while the patrollers were still busy with the ones that were coming in," said Gauteng Education Department spokesperson Steve Mabona.
"He went ahead straight to the admin block, apparently he was looking for the principal of the school and the principal was in a meeting.
"That led to him holding a knife, going for an educator who was then stabbed during that process, the other teacher we understand, shot at him."