Home prices are hitting new depths in most major US cities and are expected to fall further over the next six months.

In a majority of metro areas tracked by Standard & Poor’s/Case-Shiller, prices have fallen to their lowest point since the housing bubble burst.

Housing prices in all but one of the 20 cities tracked by Standard & Poor’s/Case Shiller fell in December from November. And the overall index declined for the sixth straight month.

Washington was the only metro area where prices rose month to month.

Eleven of the markets hit their lowest point since the housing bubble burst in 2006 and 2007: Atlanta, Charlotte, N.C., Chicago, Detroit, Las Vegas, Miami, New York, Phoenix, Seattle, Tampa, Fla., and Portland, Ore.

High unemployment, stricter lending rules and fears that prices will continue to fall are among the reasons why few people are buying homes.

A rising number of foreclosures are also weighing down prices. And as more people get stuck in depreciating homes, housing could slow the economy.

Across the country, the housing industry is recovering unevenly. Many of the cities now setting new lows have been struggling with high unemployment, more foreclosures and, in some cases, a delayed response to the housing bust in 2006 and 2007.

Homes in more established areas — those that had little room to build during the housing boom — are doing a better job holding their value. Coastal cities in California and the Northeast are seeing much smaller price declines. In Washington and San Diego, home prices even rose over the past year.