What caused the sub-prime crisis?

What's behind the USA's subprime housing mortgages crisis that triggered the credit crunch?

Here's some possible insight from this wry and perhaps accurate quote from this site:

"People used to default on their house last of all.

Now it's the first.

Many people were taken from a trailer park and put in a home.

They took a 110% loan and spent the 10% on a widescreen TV and a car.

When they lost their job, they defaulted on the house, put the TV in the car and drove back to the trailer park."

As good as this "subprime primer" cartooon! Moral hazard, indeed.

Tags: subprime, sub-prime, sub prime, mortgages, housing, credit crunch, moral hazard, Improbulus, A Consuming Experience