Robert Loomis, who guided the careers of celebrated authors as an editor at Random House for more than five decades, died on Sunday at 93, the New York Times reports.

Loomis died at a hospital in Stony Brook, New York. No cause of death was given.

A native of Ohio, Loomis first started working at Random House in 1957 and remained at the publisher until his retirement in 2011. During that time, he worked on some of Random House’s most successful books, including Maya Angelou’s I Know Why the Caged Bird Sings, William Styron’s Sophie’s Choice, and Jonathan Harr’s A Civil Action, the Associated Press reports.

Among his most notable achievements came in 1988, the Times notes, when two books he edited—Neil Sheehan’s A Bright Shining Lie: John Paul Vann and America in Vietnam and Pete Dexter’s Paris Trout—both won the National Book Award.

On Twitter, admirers of Loomis posted remembrances of the editor.

“It’s with deep sadness that I just learned that my beloved former editor, Bob Loomis, has passed away,” wrote author Lisa See. “I spoke to him a couple of weeks ago. We laughed and traded stories, as we always did. I’m heartsick.”

And Counterpoint Press vice president/associate publisher for publicity Megan Fishmann wrote, “RIP to one of the literary greats ... Bob Loomis, who was very kind to my 21 year old self and would take time out of his very busy day to regale me with amazing stories about authors like William Styron.”

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