Tom Clancy, best selling author of the Jack Ryan series, has passed away at 66. Publishers Weekly was the first to tweet out the news, with the New York Times confirming details. Many of Clancy's novels were turned into blockbuster movies, including The Hunt for Red October, Patriot Games and The Sum of all Fears. The cause of death is still unknown at this time. Clancy has another Ryan novel, Command Authority, set to be released this December.