Definition: 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.
Input: Sentence1: There was a gas leak in a house down the street. Sentence2: The people who lived there did not know. Sentence3: They left for work one day, and the gas filled up the house. Sentence4: A small spark caused the house to explode.

When they returned, they saw that their house was gone.