You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, you're given a context passage. Your job is to generate relevant questions that can be answered by directly referring to the passage.

Tracy slept awkwardly on their new bed and was having some pain, so Tracy cracked her neck.
Solution: What did Tracy do with her neck?
Why? The question asked is relevant and can be directly answered by referring to the phrase "so Tracy cracked her neck" from the passage.

New input: Few of the puffs still resided on Popstar but many left to who knows where . " Those poor lost souls ... " The knight thought to himself . He remembered falling ... falling from the sky .... The sky was so deep and dark blue ... the stars were falling . The other puff creatures were'born'this way , too . Metaknight remembered how they fell like stars .
Solution:
What may have caused the puffs to leave Popstar ?