San Francisco’s largest taxi company is on the verge of filing for bankruptcy protection, according to a leaked letter from its president.

The San Francisco Examiner, which published the December 10, 2015 letter on Wednesday, reported that Yellow Cab Co-Op is the largest taxi firm in the city, with 530 medallion holding drivers. By comparison, there are thousands of Uber drivers on the roads of San Francisco nearly every day.

The taxi industry as a whole has been under massive pressure from startup newcomers such as Uber, Lyft, and the recently defunct Sidecar . Those companies are regulated under California’s “ transportation networking company ” (TNC) law, which is separate from traditional taxi law.

Yellow Cab did not immediately respond to Ars’ request for comment. Federal court records show that the company has not yet filed for Chapter 11 bankruptcy. To be clear, this doesn't mean that the traditional cabs are coming off the streets.

“Chapter 11 Bankruptcy will allow us to reorganize our financial status and relieve us of unsecured debts,” Pamela Martinez, the company president, wrote in the letter. “It also means that our regular business will continue and we will still be able to meet all expenses necessary to operate our business. From the perspective of the individual drivers, nothing will change.”

The Examiner also noted that the company has been facing “a number of lawsuits which ended up hurting the company’s bottom line.”