It's reasonable to surmise that the government "coercion" of banks into making subprime loans may have had something to do with the recent financial crisis. I have read a number of opinions to that effect. Apparently it is wrong, however, and Martinghoul is correct. The data does not support the idea that fair housing laws had a substantial role to play in the subprime loan fiasco.
Those who have studied and written widely on this topic seem to be overwhelmingly of the opinion that the subprime loan debacle was driven by the huge demand for CDOs created by investment banks, which in turn created a demand for new mortgages to be bought and repackaged. The demand was great enough that it could only be met by lowering underwriting standards.
The collapse of the CDO market was ultimately a result of too free a market, i.e., one lacking the right kind of regulation or enforcement. Consequently, your opinion that, " A free market would have never put that capital at risk in the first place" seems incorrect. Alan Greenspan, the chief regulator of mortgages at the time, has admitted that he was wrong to have thought that banks would never act against their own best interests. After Greenspan was informed of the declining standards in the mortgage industry, he took little action because he had an abiding belief that markets would self-correct if left alone. He was wrong.
There were, of course, those in the investment banks that knew that the quality of mortgage backed CDOs was being misrepresented. They took advantage of this through the then essentially free,i.e., unregulated, credit default swap market.