(CNN) -- Author Tom Clancy, whose novel, "The Hunt for Red October" propelled him to fame, fortune and status as a favorite storyteller of the American military, has died, according to sources with his publisher and family. He was 66.

The cause of death wasn't immediately available.

A Baltimore-born former insurance agent, Clancy was known for writing meticulous thrillers focusing on political intrigue and military tactics and technology. He published 28 books -- including a new novel yet to be released.

Several were made into Hollywood blockbusters, including "The Hunt for Red October," "Patriot Games," and "The Sum of All Fears."

Seventeen of his novels appeared on the New York Times best-sellers list, according to his website. Many of them reached the No. 1 spot.

The sometimes perilous business of spy thrillers

His writings also provided the inspiration for the "Rainbow Six," "Ghost Recon" and "Splinter Cell," video game series.

His writing gained him a loyal following within the armed forces in the United States and abroad, giving him inside access that frequently informed the plots of his books. But in a 2003 CNN interview, Clancy said he was always careful not to reveal classified information or sensitive details of how the elite troops he often wrote about operated.

"I'll never decide for commercial reasons to put something in that endangers our national security. You just can't do that," he said in a 2003 CNN interview. "There was one thing, I discussed with a friend of mine in the Royal Navy. I told him a story I knew, and he said, well, Tom, you may never repeat that, as long as you live. And I haven't."

His new novel, "Command Authority," is scheduled for December publication.

Hmm, I didn't think he was very old.

Sucks.