As reported by Michael E. Miller in the Washington Post.
(To correct a false impression made by the article, nuclear weapons had already been deployed to the Cuban theater, by the time of the 1962 Cuban Missile Crisis. To make matters worse, Soviet field commanders, both on land, and at sea, had unilateral launch authority. This fact is documented, as presented at the December 2003 nuclear weapons summit held at American University, on the eve of the unveiling of the Enola Gay at the Smithsonian in Dulles, VA.
As reported in Joseph Gerson's Empire and the Bomb, a Soviet sub commander saved the world. His sub carried nuclear-tipped torpedoes. A U.S. warship, having cornered the sub, decided to have 'a little fun.' It began dropping depth charges, and succeeded in knocking out the sub's air supply. Soviet sailors were passing out. The top three commanders on board the Soviet sub had a choice. By unanimous vote, they could launch their nuclear-tipped torpedoes. To have done so would likely have escalated the Cuban Missile Crisis into a full-scale U.S.-U.S.S.R. nuclear war. But one of the commanders voted against firing, even though, for all he knew, the entire sub's crew would perish soon enough from lack of air. His decision likely saved the world.)