Analysts say new home prices show the housing industry is in a double-dip recession. Seattle might represent just a glimmer of hope based on the latest national home price index.

The Standard and Poor’s/Case Schiller index for March shows home prices overall dropped to their lowest level since 2003. Prices were down in 18 of 20 U.S. cities. Seattle was an exception, rising a tiny one-tenth of one-percent in March but still down 7.5 percent since March 2010.

Maureen Maitland, with Standard & Poor’s, says now-expired home buyer incentives from the federal government just delayed the inevitable slide in home prices that we’re seeing now.

“You usually expect to see the housing market lead an economic recovery but at this point it’s lagging which is very, very unusual and that goes to show you how bad this housing crisis [is].”

In some markets, including Detroit and Las Vegas, prices are lower now than they were ten years ago.

The only city in the Standard and Poor’s/Case Shiller index where home prices rose both on a month-to-month and year-over-year basis was Washington, D.C.

Foreclosures are helping depress the housing market, according to CBS Moneywatch editor-at-large Jill Schlesinger.

“It really could get even worse because we’ve got so many properties that have been foreclosed, so much inventory on the market,” explains Schlesinger.

The 12 cities now at their lowest levels in nearly four years are: Atlanta, Charlotte, Chicago, Cleveland, Detroit, Las Vegas, Miami, Minneapolis, New York, Phoenix, Portland, Ore., and Tampa.

The Associated Press contributed to this report.