I remember one time in primary school we were painting and because I was about 7, and kids do weird things, I put my hand in the water we used to clean our brushes because my hand felt hot and the water looked nice.
At the same age, I believe, my elementary school's lower grade would go to a dedicated upstairs art room. it wasn't used for any other purpose, and it had no carpeting, so i imagine it made it easier to clean up the messes younger kids would make doing art projects.
I can't remember what we were working on, but it involved watercolor paints. We were required to bring in an old oversized white t-shirt to wear over our uniform to protect us form spills and such. Having read some kid's book that featured a mechanic covered in grease, I proceeded to put some brown/black watercolor randomly on my art shirt just to look like said mechanic.
There was a kid who decided to smoke a blunt in the first floor bathroom of my high school's academics building. Apparently, a teacher or maybe another kid was going to come into the bathroom, so the guy freaks out and tosses the lit blunt into the bathroom trash full of paper towels. The trashcan immediately erupts into flame.
During my freshman year, I was taking a social studies course and our teacher - a rather well-loved older woman who was a very easy teacher, generous grader, and proud owner of a red sports car many students sperged about (especially the rare few that got to ride in it). One morning, she asks if anyone used one of our bathroom passes
x number of days earlier. Everyone shrugs and either answers no or that they aren't sure. Apparently, someone set fire in one of the bathroom trash cans at the same time our class met, so every teacher that had a class that hour was asked to identify anyone who might have been using the bathroom at the time of the incident.
Some days later, my teacher reads her daily report - a photocopied document that had information about absences, transfers, and suspensions - and notices a student or two with a suspension code she doesn't recognize. As she would normally do when she didn't recognize a suspension code, she asked me to look it up in my handbook because it listed all the different codes used to identify reasons for suspension. As an example, I still know to this day that frequently-cited code numbers 4 and 11 were for insubordination and unexcused absence from a detention period.
When I looked up the code she gave me, I reported that it was for arson; the culprits had been presumably identified and suspended. I don't recall if she named them or not. I'm thinking she didn't as it would have been a huge privacy violation otherwise - and likely enough to get her fired. I believe she taught another 10-15 years before she finally retired - amazing because my classmates and I thought she looked old enough to be our grandmother and would retire at any time.
my brother almost got the STEM teacher in trouble by along with my cousin putting "bush did 9/11" and "virginity rocks" on the projector on the ceiling without him knowing. his bosses saw it but he doesnt know it was them.
My senior year, the physics teacher had a projector setup where there was a roll of transparent plastic that a teacher could scroll back and forth to review past notes and get more blank space. This was then displayed on a movie screen for maximum readability.
For whatever reason, I decided to go to the projector before class started and I wrote "911 is a joke" on the plastic. Later, our teacher turned on the projector to illustrate a problem. He lowered the screen and read "911 is a joke" out loud, visibly confused and totally clueless as to what it meant and why it was there for everyone to see. When someone finally told him it was the name of a song by Public Enemy, he reacted indifferently and continued with whatever he wanted to show us. He never asked who did it, and I never confessed.