The tragedy is that the foundation for the crisis was clearly evident through the actions of the key players in the financial markets. This crisis was an a result of some economic shock that hit the housing market but a a combination of incentives and structures coupled with loose monetary policies that lead to greater risk taking than should have occurred.
Shame on the government not for doing too little after the crisis began but setting up an environment where the excesses could have occurred. This has less to do with lending practices at the point where the mortgages were originated and more to do with an environment that allowed the mispricing of risk. The cost of mispricing risk will take years to clean-up.