Toys “R” Us, one of the world’s largest toy store chains, has filed for bankruptcy protection, becoming the latest casualty of the pressures facing brick-and-mortar retailers.

The company made the Chapter 11 bankruptcy filing late Monday night in federal court in Richmond, Va., acknowledging that it needed to revamp its long-term debt totaling more than $5 billion.

The retailer, which also owns Babies “R” Us, has struggled to compete with Amazon and stores like Walmart.

But the financial plight of Toys “R” Us was exacerbated by a heavy debt load that has weighed on the company for years. The private equity firms Kohlberg Kravis Roberts and Bain Capital, as well as the real estate firm Vornado Realty Trust, purchased the company in a leveraged buyout for about $6 billion in 2005.