Lehman Brothers filed for Chapter 11 bankruptcy protection on September 15, 2008 -- the largest bankruptcy filing in U.S. history, with over $600 billion in assets in its portfolio.
The collapse of Lehman was attributed to its deep investments in subprime and other lower-rated mortgages and related securities.
Before it collapsed, AIG, as measured by asset value, was the largest insurer in the world. But in September 2008, after its credit rating went down, AIG was caught without enough collateral for the credit default swaps it had sold to banks around the world, and was forced to accept a massive federal bailout package in order to forestall a collapse. As the size of the company's debts have grown, the U.S. government has readjusted the terms of the bailout, and gradually begun to take over parts of the company.
