In this task, you're given a four sentences of story written in natural language. Your job is to complete end part of the story by predicting appropriate last sentence which is coherent with the given sentences.

Sentence1: My sister's graduation ceremony was finished. Sentence2: The Principal and Staff announced to everyone that they can leave. Sentence3: While people were moving down from the upper seats, a fight broke out. Sentence4: Two people were wrestling with each other.
In addition, one fell down the stairs.