The signs that smaller retailers are struggling are unavoidable at malls across America: "Going out of business" sales at many Wilsons Leather stores. "Up to 70 percent off" at KB Toys. At the once-sizzling Paradise Valley Mall in Phoenix, the space once occupied by Bombay Co., the furniture chain that went bankrupt last year, is empty. Wilsons just finished liquidating its inventory. KB Toys, AnnTaylor and American Eagle feature bold posters advertising steep discounts. "I don't think it brings much business when all these stores are closed," said Michelle Green, a sales clerk at Fred Meyer Jewelers. Around the US, mall centers are starting to feel the recoil from a rapid expansion in recent years that allowed retailers to aim stores at almost every niche, from shoppers who wanted Talbots clothes for their children to those who craved Bombay's little wood tables. Now, consumers who are closing their wallets amid rising gasoline prices and a housing slump are forcing specialty retailers to pare back their brands. While still healthy overall, mall centers in areas hardest hit by the housing downturn - like Paradise Valley - are suffering the most store shutdowns. Retailers including AnnTaylor Stores Corp., Talbots Inc. and Pacific Sunwear of California Inc. have closed hundreds of stores so far this year. Gadget seller Sharper Image Corp. filed for bankruptcy protection last month and plans to shutter nearly half of its 184 stores. That retrenchment, along with the Chapter 11 bankruptcy of catalog retailer Lillian Vernon Corp., marks the beginning of a wave of retail bankruptcies that's expected to go well beyond the home furnishings stores hurt by the housing malaise. "This is economic Darwinism," said Dan Ansell, a partner at Greenberg Traurig LLP and chairman of its real estate operations division. "Those retailers and businesses that have a product that is desired by consumers will survive, and those who do not will not." Unless the economy dramatically improves, Ansell believes retail bankruptcies this year could reach the highest level since the 1991 recession. More closings could leave gaping holes in the nation's retail centers, which have already seen average vacancy rates creep up to between 7 percent and 8% from 5% over the last six months, according to data from NAI Global, a commercial real estate services firm. David Solomon, president and CEO of ReStore, NAI Global's retail division, expects the vacancy rate could hit 10% by the end of the year. Suzanne Mulvee, senior economist at Property & Portfolio Research, figures that vacancies could rise as high as 12.5% this year. Her figure includes retail spaces where tenants have defaulted on their rents. Part of the problem, according to Mulvee, is that more retail space is coming to the market just as consumer demand is falling. Another 12 million square meters of retail space will become available this year, she predicts, on top of last year's 13.3 million. That is well above the average 9.3 million sq. m. added per year earlier in the decade. As a result, markets like Phoenix, which had a retail boom, are expected to see the most dramatic increases in vacancies. Phoenix's rate is expected to more than double to 10% by the end of 2009 from 4.4% late last year, according to Property & Portfolio. In Kansas City, Missouri, rates could rise to almost 17% by the end of 2009 from last year's 13.5%. In San Antonio, experts say the figure may hit 20.5% next year from last year's 17.4%. Still, Solomon doesn't think the situation will be as dire as in 1991, when the savings and loan crisis hurt the entire country. Experts also say merchants are weathering downturns better because of new systems to control inventory and costs.