Long story short, our banks decided to lump together morgages into sellable objects to make money, and since a certain small proportion of individual mortgages went under, no one wanted to buy packages since no one knew which bundles held bad mortgages.  This occurred after our government pushed to deregulate exactly such a thing.  In short, our financial speculators and investment banks wanted to make lots of money, and so they did something risky, and we are the ones to pay.  We are going to pay the effects of inflation when things become less affordable; we will pay more proportionally as our dollar drops because each dollar means more to us in proportion of our income.  We will pay to bail out these banks, as taxes have been reduced disproportionally for the wealthy and we are left to foot the bill when our government bails out the rich.  We will pay if the bailouts don’t work and our economy collapses, because we have no golden parachutes, little mobility, and we will be the first to suffer unemployment.

On every level, the irresponsibility of the capitalist class and financial capital specifically will affect the middle and lower classes (or the working class specifically if you want to use ‘class’ as Marx defined, and not Weber), and all because those in finance capital wanted to make money and started to do unsafe things–at the allowance of the government.