sounds like my school.I remember seeing the janitor at my high school wheeling a bucket of blood-stained mop water back to the utility room. He had just mopped up the hallway from a kid getting knifed in the gut.
It wasn't a shocking thing at the time. I just remember thinking I was glad to have never had a broken limb or knife wound by the end of 9th grade.
i was surprised at how little blood resulted from a kid getting thrown through a plate glass window in our cafeteria.