Stanislav Petrov

In 1983, 21 years after the Cuban Missile Crisis, the USSR reported that the USA had launched an intercontinental ballistic missile and it seemed like a third world war was coming. Except, it was a nasty false alarm.
How so? We can thank engineer Stanislav Petrov for reporting that the computer in the command centre that was reporting the supposed attack was faulty. What was an engineer like him doing there? The usual officer was unable to show up for duty that night. After contacting command about the fault, he waited nervously and within 23 minutes, he became the man that saved the world. There was no need to alert the top commanders who would've immediately retaliated. It was now clear that there was never any missiles heading for Russia. Stanislav disclosed about his heroic deed 10 years later. It just goes to show that not all heroes wear capes.