one time, last year, during P.E we(the class) were waiting for the coach at the begining of class. 2 guys were tossing a football around, and one of them threw it too high and hit the sprinkler on the ceiling. what came out wasnt exactly water, but a black sludge that smelt like sewege. luckly for me, i was far away and didnt get any on me, but one guy was under it and got soaked in it. so the school was evacuated, which i think was pointless, while they cleaned it up. good ting was that we got to miss P.E. bad thing was it smelled like crap for a long time.