UPDATE: Top 10 of the Bottom housing markets in USA.

1. Las Vegas, Nevada: Home prices dropped from 2006 to 2009 more than 56%...according to Moody's Economy.com . More than 81% of single-family home mortgages in Las Vegas had negative equity in the fourth quarter of 2009, according to Zillow. It may take more than 20 years for the prices to get back to where they were in the peak.

2. Merced, California: As real estate became increasingly unaffordable in the bigger cities like San Francisco, many would-be homebuyers started exploring options in smaller markets, such as Merced. This trend increased real estate demand in Merced, prices appreciated even faster as exotic mortgage products and investor interest hit the market. Area home prices jumped nearly 129% from 2002 to 2006.

3. Phoenix, Arizona: Home prices in Phoenix jumped more than 101% from 2002 to their 2006 peaks.Home prices dropped more than 52% from their peaks through the third quarter of 2009. And as of the fourth quarter of last year, nearly 62% of single-family home mortgages were underwater, according to Zillow.

4.Orlando, Florida: Easy credit to home buyers and the demand helped send home prices surging by more than 102% from 2002 to the market's peak in 2006. The nearly 48% drop from the peak through the third quarter of 2009 has pulled 58% of single-family home mortgages in Orlando underwater, according to Zillow.

5:Greeley, Colorado: With 45% of single-family mortgages underwater, the Greeley, Colo., market has among the higher concentrations of negative equity in the nation. Many of these buyers began falling behind on their payments, area foreclosures surged, and home prices fell about 15% through the third quarter of 2009.

6. Bend, Oregon: From the years of 2002 to 2007, the prices of homes in the city of Bend leaped by 99%, as second-home buyers and retirees were drawn to this community. It seems that initial phase of the downturn was triggered by evaporating demand from second-home buyers. Then unemployment rose and a large number of home owners were not able to make their house payments. As of the fourth quarter of last year, roughly 41% of single-family home mortgages were underwater, according to Zillow.

7. Minneapolis-St. Paul: Real-estate values increased nearly 34% from 2002 to 2006. The president of the Minneapolis Area Association of Realtors, says subprime lending played a key role.

8. Memphis, TN: Even though the prices of homes did not increase as much as others in the boom, there were pockets of SubPrime mortgages that created a high concentration of negative equity.

9. Cleveland, OH: The prices of homes increased by 13% from 2002 until 2006 and were followed by a 16% decrease through the 3rd quarter in 2009. Subprime lending exposure has also played a role in the real-estate market's decline in this city. Roughly 32% of single-family home mortgages were underwater as of the fourth quarter of last year, according to Zillow.

10. Grand Rapids, Michigan: The values of real estate in this city increased 15% from 2002 to 2005 and then fell about 13% through the third quarter of last year. As of the fourth quarter of 2009, roughly 29% of single-family home mortgages were underwater, according to Zillow. The declining economy has also been linked to the weakness of the housing market.