It's a bad day for anyone trying to sell a home in the world's largest economy.

Housing prices fell in March to their lowest point since the downturn began, wiping out gains made over the past two years.

The Standard & Poor’s Case-Shiller Home Price Index for 20 large cities fell 0.8 percent from the previous month.

That's eight straight monthly drops. Housing prices in the U.S. have tumbled more than 33 percent from their July 2006 high.

“Home prices continue on their downward spiral with no relief in sight,” David M. Blitzer, chairman of the S.& P. index committe, said rather bleakly in the New York Times. 

The news, while grim, is hardly a surprise, and it's certainly not good news for the U.S. economy as a whole.

People buying homes — and then filling them up with stuff — has been a key driver in an economy where consumer spending makes up about two-thirds of GDP.

“Weak demand and a deluge of discounted sales of distressed properties have weighed significantly on prices,” Aaron Smith, a senior economist at Moody’s Analytics told Bloomberg.

“It’s hard to be enthusiastic about the economy’s prospects as long as house prices are falling," he warned.

For more on today's news, Nick Timiraos of the Wall Street Journal's Developments real estate blog has put together a handy Q&A.