Chavie,
This reminds me of a story I heard from a friend named Saki:
There was onced a girl who was famous among her friends for her tznius. When her classmates would wear unsuitable clothing she would dress appropriately, and made sure to tell them how they should be dressing. Even when her classmates wore clothing that complied with her school’s dress code, she made sure to tell them if she felt their clothes were inappropriate.
Her teacher was so impressed by this behavior that she gave her a special “tznius medal” to wear on a chain (under her clothing of course). Unfortunately one day she was busy telling one of her nebach classmates that her skirt was the wrong type. As a result she missed the first bell and was running to class so she wouldn’t be late. Suddenly her “tznius medal” slipped and she tripped on it and fell down the stairs. Despite the many thousands who said tehillim for her she died.