My freshman year there was a science teacher doing a lab that required students to bring a jug of milk (I don't know what the lab was, but i guess it required a full jug). One student tried to put their jug in their locker, but put it in the wrong one (many people didn't put locks on their lockers). The owner of the locker came back and found a full gallon of milk in their locker and awkwardly set it on the ground outside of their locker and left it there. This prompted some teacher to see it as a suspicious object, and reported it. Before we knew it, we were evacuated from our classes to the football field. Moments afterwards, the bomb squad arrived and went in. We were dismissed from school but many people had left their keys and wallets inside, and the school hadn't been "cleared" yet. About four hours afterwards people were allowed to come back and get their stuff but many couldn't and left their bags in their classes. It was a huge mess and it messed up all the teachers' schedules and the next day for the kids was spent finding their bags in their 5th period class when the evacuation got called. Even better was the fact that the jug was spoiled milk, despite the police saying it didn't seem to be milk and that it was expanding at "a slow rate".