Not exactly a stupid thing but this happened during my third year in high school. There used to be this kid who used to dress weird, was socially awkward, would always stay alone and never talk to anybody, so he was constantly bullied in his class. He was two years younger than me so I didn't know him at all. That year the student council had organized this huge event called "Up To Us" where the school closed off for two day days and during that time the students would paint their own classes based on the floor they were on: the first floor had all classes painted green, the second red and the third blue.
They also asked us to bring adults with experience so I asked my dad and he came to help.
By the end of the second day, my dad and I were in the hallway chatting with the teachers when we heard a scream. We turned and saw a student running towards us with blood dripping from his face being chased by the kid I mentioned earlier. Basically the kid, tired of the constant bullying, had brought a blade to school that day and when one of the bullies approched him, he attacked and cut his face.
My dad went after them and restrained the kid, they theb called his parents and I believe he got suspended.