Bear Sterns and Lehman did not cause the crisis. Every bank was holding onto large amount of mortgage back securities that were toxic. Bear Sterns and Lehman while not famous in the commercial world we’re big in the investment world. So, when these two began to fail it became apparent to everyone on Wall Street just how serious the situation was and the banks began to panic. Several other banks had so many toxic assets that they would have easily failed if the U.S. government did not step in.

I research a little bit more about the financial crisis itself, and you’ll get a better understanding of what was going on. Heck, watching the big short is a good introduction.