The REAL moment the Cuban Missile Crisis nearly erupted into war

Declassified documents, revealed at a conference on the Cuban Missile Crisis in Havana, show that events edged closer to global nuclear war than previously thought.

The most dangerous day of all was apparently October 27, 1962 - when a US Navy destroyer dropping depth charges off the Cuban coast almost accidentally hit the hull of a Soviet submarine carrying a nuclear warhead.

The U.S. military "did not have a clue that the submarine had a nuclear weapon on board," said Thomas Blanton, director of the National Security Archives.

The nonprofit archive at George Washington University collected many of the documents for study during the three-day conference back in 2002.

The depth charges "exploded right next to the hull," Vadim Orlov, the submarine's signals intelligence officer, said in a written account of the incident. "It felt like you were sitting in a metal barrel, which somebody is constantly blasting with a sledgehammer."

At first, submarine crew members considered using the nuclear weapon, thinking war had erupted. But they ultimately surfaced, showing themselves to their American pursuers and defusing the tension.