The low-fare carrier has struggled to find its footing after its planned merger with JetBlue was blocked by a federal judge.

Spirit Airlines filed for Chapter 11 bankruptcy Monday, just days before the holidays and months after it failed to merge with another airline. While this announcement comes before the busiest travel weekend,

The airline listed its estimated assets and liabilities in the range of $1 billion to $10 billion each, according to a court filing on Monday.