I think a lot of people on all sides just turned a blind eye.
The lenders kept lending to people that couldn't afford the payments.
The buyers kept buying more than they could, knowing they had no room for error.
The fed kept lowering intrest rates to keep the markets artificially high.
Gas broke the camels back. All of a sudden the $7 cup of coffee and any other discretionary spending went away. People suddenly had to shift money away from their mortgages to buy gas to get to work. Investors had nowhere to turn so they jumped into oil futures, which only compounded the issue. At some point, it broke and it broke big.
I have no formal training on the subject of the economy but amid the tripe from the media, industry and our government (this all just hit us without warning! the sky is falling!)I wonder if things would be this bad right now if the powers that be would have just let things take their natural course a few years ago.