RadioShack's recent decision to close more than 1,000 stores is a prominent sign of the struggles facing retailers. RadioShack is not alone. In recent years, the Gap has closed 20% of its locations. Even Macy's, which has forecasted strong earnings and is considered the most successful of the mid-market retailers, closed stores recently. Brick-and-mortar stores have been suffering from slow economic activity for years, as well as from increased competition from online retailers, reports 24/7 Wall St. Weakened companies cannot afford the real estate and personnel costs that go along with supporting hundreds of unprofitable locations. Among those that have shut the most number of stores are Barnes & Noble, J.C. Penney, RadioShack and Toys "R†Us.  The hipster retailer Abercrombie & Fitch tops the list. Mergers and acquisitions activities, competition from online stores, decision to shift to new markets, and strategic overhauling plans are some of the reasons why retail chains close stores. 24/7 Wall St. notes in particular that "the rise of Amazon.com, America's largest e-commerce operation, has turned the entire retail industry on its head.†To determine the retailers closing the most stores, 24/7 Wall St. reviewed large retailers that have publicly announced store closings for 2014, or are in the middle of a multi-year plan to trim locations. In addition, it reviewed company earnings and SEC filings. Here are nine retailers closing the most stores: Abercrombie & Fitch Headquarters: New Albany, OH Retailer first announced its plans to close 180 stores by 2015 more than two years ago. The retailer is planning to shift marketing for its Abercrombie & Fitch to older shoppers; while transforming its Hollister stores to a fast-fashion approach in line with H&M and Zara. Barnes & Noble Headquarters: New York With book retailing shifting to the Internet and e-books, early last year, Barnes & Noble plans to shut a third of its stores over the next 10 years. As of this January, the company had closed some 14 retail locations, including its one-time flagship store in New York City. Aeropostale Headquarters: New York Aeropostale is in the midst of closing 40 to 50 stores in 2014, and plans to shutter some 175 stores in total over the next few years. The retailer is facing pressure from competitors such as Gap and Abercrombie & Fitch, as well as declining mall sales. J.C. Penney Headquarters: Plano, TX At the start of 2014, J.C. Penney announced 33 store closings, to be completed by May. As of November last year, the company had 1,095 department stores, down only slightly from past years. The retail giant reported surprisingly strong earnings in February. Office Depot Headquarters: Boca Raton, FL Following its merger with rival OfficeMax, the company had 1,912 retail stores at the end of its latest fiscal year, including 823 OfficeMax stores. Since the merger, the company has closed 15 of its Office Depot stores and seven OfficeMax outlets. RadioShack Headquarters: Fort Worth, TX The retailer recently announced it would close 1,100 out of its more-than 5,000 stores, as part of its cash-management and turnaround plans. Sales declined 19% at stores open at least a year because of lower foot traffic and weak performance in mobile sales. Sears Holdings Headquarters: Hoffman Estates, IL Sears has been heading downhill since 2005, when Sears Roebuck & Co. merged with Kmart in a deal worth $11 billion. Since 2010, the company has closed roughly 300 stores. Staples Headquarters: Framingham, MA Staples recently announced plans to close 225 stores, or roughly 12% of its total count, by the end of 2015, as part of its shift away from brick-and-mortar business to online retail. Toys "R" Us Headquarters: Wayne, NJ There are reports that the company will soon close some 100 stores. Disagreements among the company's ownership and a high debt burden have weighed down the retailer. RELATED: J.C. Penney to Close Stores and Layoff 2,000 Workers