Answer:
Cuban Missile Crisis- Sub incident
How it impacted my day to day life: I probably wouldn't be born.
October 27, 1962: A aircraft was shot down by the Soviets while over Cuba, killing its pilot, causing tensions to escalate to their highest point.
Later, a Soviet submarine was detected trying to break the blockade that the US Navy had established around Cuba. In response the destroyer USS Beale dropped fake warning torpedoes an attempt to make the submarine surface.
But while the action was designed to encourage the Soviet submarines to surface, the crew of B-59 had been incommunicado and so were unaware of the intention. They thought they were witnessing the beginning of a third world war. The captain of the sub, Valentin Savitsky, thought the submarine was under attack and ordered to prepare the submarine's nuclear torpedo to be launched at the aircraft carrier USS Randolf.
All three senior officers aboard the B-59 had to agree to the launch before it happened. Fortunately, the B-59's second in command, Vasili Arkhipov, disagreed with his other two counterparts, and convinced the captain to surface and await orders from Moscow.
Had it been launched, the fate of the world would have been very different: the attack would probably have started a nuclear war which would have caused global devastation, with unimaginable numbers of civilian deaths.
I think it's D. primary source.... not 100% sure
