Home owners who are underwater on their mortgages are increasingly concentrated in the Rust Belt, while West Coast homeowners are less likely to be in negative equity, according to the first quarter Negative Equity Report from Seattle-based Zillow.

Nationally, 12.7% of homeowners with a mortgage were in negative equity, down from a peak of 31.4% in first quarter, 2012.

For several years, Las Vegas was most illustrative of the housing bubble and bust, with nearly three-quarters of mortgaged homeowners underwater when the market bottomed out in in the first quarter of 2012. But Chicago now has the highest negative equity rate among large U.S. markets, passing Las Vegas in the first quarter of this. At bottom, Chicago had a 41.1% rate of negative equity, but recovery has been sluggish and the negative equity rate has declined more slowly than elsewhere.

In first quarter 2012, the West Coast, Southeast, and Rust Belt regions had a disproportionately greater share of underwater homeowners. For example, the Southeast had 20.4% of homes with a mortgage, but 24.9% of homes in negative equity.

Four years later, the West Coast, home to hot markets like the Bay Area, Portland, and Seattle, is at 10.2% of homeowners with negative equity, but 15.2% of all mortgaged homeowners. The imbalance was worst in the Rust Belt region, which includes Wisconsin, Illinois, Indiana, Michigan and Ohio.

"When the housing bubble burst, the West Coast had more than its fair share of underwater homeowners," said Zillow Chief Economist Dr. Svenja Gudell. "But the strong local economy and job markets have significantly helped these housing markets recover, and several are now more expensive than they were during the housing bubble. Other parts of the country didn't get those same benefits, and until market fundamentals improve, home owners and buyers in these areas will be facing disproportionately higher levels of negative equity as they navigate the housing market."

Four of the 10 metros with the highest rates of negative equity are in the Rust Belt. Meanwhile, the West Coast is home to five of the 10 metros with the lowest levels of negative equity.