For decades, The Charleston Gazette-Mail in West Virginia has exposed corruption, greed and incompetence with a tenacity that was rewarded last year with journalism’s highest honor, a Pulitzer Prize. But the newspaper now faces a painful reality: No matter how strong its journalism, no publication is immune to the economic pressure on the industry.

On Monday, staff members learned that the newspaper was filing for bankruptcy ahead of a sale, ending the Chilton family’s century-long role in shepherding its journalism. A prospective buyer is lined up, but the move raises questions about the future both of a relentless local watchdog and its more than 200 employees, including Eric Eyre, who accepted the Pulitzer last year for his reporting on the state’s opioid crisis.

“Never in a million years would I think that eight months later we would be in bankruptcy and I’d be reapplying for my job,” said Mr. Eyre, who plans to remain in West Virginia no matter the outcome. “But I guess life is full of highs and lows, and obviously now we’re at a low.”

The announcement came at the end of a tumultuous period for the publication, which had weathered drawn-out legal battles stemming from a 2004 transaction in which the left-leaning Charleston Gazette acquired a controlling interest in the right-leaning Charleston Daily Mail. The newspaper — which has about 32,000 daily subscribers, according to a court filing — has also suffered circulation and advertising losses over the past decade that its publisher, Susan Chilton Shumate, described in a letter on Monday addressed to the staff as “devastating to the bottom line.”