As with Bear Stearns, the subprime mortgage crisis led to the demise of fellow investment bank Lehman Brothers. At the time of its collapse, it was the nation's fourth-largest investment bank, with around 25,000 employees across the globe, according to the History Channel. By 2007, Lehman Brothers had $111 billion in real estate-related assets and securities, so when the real estate market took a tumble, Lehman reported its first losses since 1994. In September 2008, Lehman Brothers declared bankruptcy with $639 billion in total assets and $613 billion in debts, making it the largest bankruptcy filing in U.S. history.