I worked at Old Navy when I was 16, and here are a few things that happened:
1) Someone egged the store.
2) Someone tried to break in the store AT 10:30 when several of us were still on the clock. I really had no idea what the hell was going on though, I was in the back and I heard this alarm blaring.
3) I found anal lube and a syringe in the bathroom! Gross!!!
4) People would always MISS the toilet and take a dump on the wall or floor. It was like a game of who can miss the toilet: piss on the toilet paper and crap on the wall all day everyday.
That job really blew. I remember folding the same pile 20 times in one day. I even stood there like a hawk trying to protect it but people would ruin it right in front of me! However, I do appreciate those people now because if they didn't keep making a mess I wouldn't have had a job at that age.