A significant portion of the collapse was due to people not doing their due diligence, trying to make money for free, taking out loans that they knew they couldn't maintain past the short term. I saw them, talked to them, they told me to jump on board and ride the real estate balloon up...easy money. And of course it was for a while. Many responsible people were hurt by the recession, and possibly lost homes when they lost jobs, but the greed fest that blew up went all the way from baristas with mortgages on several properties right up to the marketers of opaque, heavily leveraged, and exotic mega financial "products".