The city of Detroit filed for Chapter 9 bankruptcy on Thursday afternoon.

Detroit’s emergency manager, Kevyn Orr, filed the request to begin what will be the biggest municipal bankruptcy in United States history. Chapter 9 status would shield the municipality from some $18.5 billion in debt and other liabilities.

The decision to file for bankruptcy required the approval of both Orr and Michigan Gov. Rick Snyder (R). Orr was appointed by Snyder to try and salvage the city’s finances, which reached a crisis point amid a steady decline in population and tax receipts.