I really dont know man, my whole secondary school was a fuckin mess with false rape accusations and that autistic girl and being picked on by the other kids and shit. I got my watch stolen in year 7 (american 6th grade) but it was just a casio or whatever. I used to get beaten up a lot then but it was mostly psychological shit.
Aside from our visits to churches we had 1 real school trip which was a coach journey to germany just to visit a couple museums or whatever. On that trip outside the cafeteria the entire year grou on the trip (130+ people) was out the back while all the teachers were inside so we were unaccompanied. A group of kids grabbed me and stripped off all my clothes while every girl I knew laughed at me. Then they threw me in the bushes when a teacher came out to check out what the noise was about. I remember that incident quite well.
Also on the coach journey back no one sat next to me so I was on the back row by the window next to a teacher who had headphones in, and I didnt have a phone or ipod or whatever with me. And there was a major road accident in belguim causing us to miss our ferry and get home even later. So I spent 10+ hours in the back corner of a coach with no one to talk to or nothing to do. So that kinda sucked. But I was used to that type of shit happening.
I really cant think of a particular "worst thing" tho