The bankruptcy of Lehman Brothers on September 15, 2008 was the climax of the subprime mortgage crisis. After the financial services firm was notified of a pending credit downgrade due to its heavy position in subprime mortgages, the United States government summoned several banks to negotiate financing for its reorganization. These discussions failed, and Lehman filed a Chapter 11 petition that remains the largest bankruptcy filing in U.S. history, involving more than US$600 billion in assets.