The proliferation of online shopping sites has enabled people to shop comfortably in their own homes. However, the popularity of e-commerce sites also signaled the death of brick-and-mortar stores, and now, it’s likely that two of the most popular retailers in America may be shuttering their doors permanently.

It was reported that Sears and Kmart may be closing their stores for good. Sears has been a fixture of American culture as it has been around for more than a century, while Kmart has been around since 1899.

According to the New York Times, the corporate owner of Sears and Kmart, Sears Holding Corporation, said that there is “substantial doubt” that it could continue operating in a filing with the Securities and Exchange Commission.

“Our historical operating results indicate substantial doubt exists related to the company’s ability to continue as a going concern,” it said in the filing.

Although the owner cited efforts to cut costs, sell a property, and acquire new funding sources, the corporation still reported a $2.2 billion loss last year. Sears Holding Corporation is said to be using money from its investments and financing activities to fund operations at Sears and Kmart.

According to the report, both stores have suffered because they were in older shopping malls and neighborhoods. Moreover, people have been flocking to rivals Walmart and Target due to their deep discounts and more attractive aesthetics. Online shopping with giant e-commerce site Amazon has also affected Sears and Kmart’s sales.

With fewer people going to the mall and more online competition, it has been confirmed that more brick-and-mortar stores, apart from Sears and Kmart, will be closing down in the next few months.

USA Today reports that J.C. Penney will be closing down 138 stores this year. The stores will begin liquidation sales next month and will close in June. Electronics and appliance retailer HHGregg, which filed for Chapter 11 bankruptcy protection, will be closing 88 stores. Macy’s will be closing 68 stores, while RadioShack will be closing 187 stores.

The most store closings will be done by Payless, as the discount chain footwear be shutting the doors of as many as 500 stores, as previously reported by Jobs & Hire.