Pulitzer Prize–winning journalist and author Jim Sheeler, who was a National Book Award finalist in 2008 for Final Salute: A Story of Unfinished Lives, has died at 53, the Denver Post reports.

Sheeler, a Texas native, worked for years as a journalist in Colorado, specializing in writing obituaries. In 2007, he published Obit: Inspiring Stories of Ordinary People Who Led Extraordinary Lives, a collection of obituaries of remarkable people whose deaths otherwise might have gone unnoticed by the public at large.

He followed that up in 2008 with Final Salute. The book, about a U.S. Marine Corps major tasked with notifying the families of soldiers about the deaths of their loved ones, was based on a feature article Sheeler wrote for the Rocky Mountain News that earned him a Pulitzer Prize for feature writing.

In a starred review, a critic for Kirkus praised Final Salute as containing “sobering, touching stories told with deep respect.”

Sheeler’s admirers and colleagues mourned him on social media. Journalist Steve Knopper tweeted, “I am devastated to share the news that my dear sweet beautiful talented accomplished empathetic forever-young friend of 30 years, @jimsheeler, has passed away. He would want us to share stories. I will, too, as soon as I stop crying.”

And reporter Wesley Lowery wrote, “This is devastating. I was texting with Jim just last week, playing phone tag trying to find time to hop on the phone. Final Salute is one of the best, most empathetic writing I’ve ever read. Jim will live on through his writing.”

Michael Schaub is a Texas-based journalist and regular contributor to NPR.