Experts are debating the true catalyst behind the onslaught of retail bankruptcies filed this year, looking beyond e-commerce competition and excess real estate to another culprit: private equity firms.

Many retailers that filed for bankruptcy protection this year were bought out by private equity firms within the last 10 years. True Religion Apparel is owned by TowerBrook Capital Partners, Payless ShoeSource Inc. was acquired by Golden Gate Capital and Blum Capital, and Gymboree Corp. is owned by Bain Capital. Lawyers working on behalf of creditors worry these buyout firms played a hand in exacerbating many retailers’ struggles by forcing them to take on a crippling amount of debt that led to their bankruptcy, the Wall Street Journal reports.

In a court filing, Payless creditors said “the depletion of their coffers put the company on a dangerous path that ultimately led to this instant bankruptcy filing,” the Journal reports. According to S&P Global Market Intelligence data, since 2010 there have been about $90B in leveraged loans and bonds raised for retailers owned by private equity firms.

Though overleveraged retailers are at a greater risk of failing, owing heavy debt loads is but a single factor when it comes to industry woes. The sector is undergoing a seismic shift due to chasing consumer shopping preferences that is forcing retailers to adapt — and those that cannot adapt are being left behind.