It's one of two things for you @
Lequte: you either attended a private school or a relatively tame public school.
In my secondary school, staying in school was optional. No matter how much cash was spent reinforcing the walls, students always broke a section down for their willful exits at any time of the day. They called it the 'Golden Gate.'
When I was in JS3, I had to chase down a boy (actually, a man; I was the boy), being the class captain, at the behest of my teacher. The boy fled because she wanted to flog him for incomplete notes. I got to Golden gate where I saw, for the first time in my life, boys having sex with girls on the bare floor. Anyway, I was apprehended and stripped of my feedieng money, harrassed and sent back to school.
Several girls were raped on graduation day in my school. Others were killed. The 'Capone' during my time was a science student who was stuck in SS1 'til I graduated.
These are not things I heard. They were things I saw firsthand. A corper teacher was raped when I was in SS2. My entire class was punished for it, save me. (I was really tiny even in Senior school and they knew I couldn't have done it.)
Students have beaten male, mature teachers into a coma before my eyes.
Unless you're referring to a much older era, I daresay this has been the norm for a very, very, very, very long time.