One example could be in a very crowded concert or event. If a girl is in the middle of a large, rowdy crowd, her skirt might accidentally get caught on something or pulled by someone moving through the mass of people. For instance, at a music festival, people are often jumping and pushing to get closer to the stage. A girl's long flowing skirt could get caught on a fence or someone's backpack strap and rip off.
In a sports event at school, like a track and field meet. There could be a situation where a girl is running in a skirt for a race. If she accidentally trips over another runner's foot or a small obstacle on the track, she might fall in such a way that her skirt gets ripped. This can be really embarrassing for her, but it also shows how unexpected these situations can be in a busy and active environment.
During a school play, there might be a lot of chaos backstage. If a girl is wearing a costume with a skirt and has to quickly move around props and other actors, she could get caught on something. Maybe she's running to get on stage in time and her skirt gets caught on a nail or a piece of scenery, causing it to rip off. This not only affects the girl's performance but also her confidence during the play.