Stanislav Petrov, the Soviet officer credited with saving the world from a potential nuclear war disaster in 1983, has died in Russia.
The former lieutenant colonel, who prevented the USSR from erroneously launching a nuclear attack on the US, died on 19 May 2017 aged 77 at his home on the outskirts on Moscow.
On 26 September 1983, Petrov was on duty monitoring any potential missile attacks against the Soviet Union during the Cold War. According to the early radar warning system, the US had fired a missile towards the Soviet Union, with apparently several more on their way.
At the time, Moscow's response would have almost certainly been to launch a nuclear attack on the US in retaliation. However, rather than informing his superiors, as per his instructions and training, Petrov thought the missile attack was a false alarm due to a system malfunction.
Petrov's decision, which was later revealed to be completely accurate, prevented a nuclear attack from the Soviet Union which would have caused unimageable consequences and arguably the end of the word itself.
News of his death is now only just being heard after Karl Schumacher, a political activist from Germany who helped reveal his story to the world, rang Petrov to wish him a happy birthday, only for his son to inform him he had died several months ago, according to RT.
Speaking to the BBC on the 20th anniversary on his decision which prevented WWIII, Petrov said: "The siren howled, but I just sat there for a few seconds, staring at the big, back-lit, red screen with the word 'launch' on it.
"A minute later the siren went off again. The second missile was launched. Then the third, and the fourth, and the fifth. Computers changed their alerts from 'launch' to 'missile strike'.
"All I had to do was to reach for the phone to raise the direct line to our top commanders - but I couldn't move. I felt like I was sitting on a hot frying pan."
Instead of giving the go-ahead to launch an attack, he called the on duty officer in the Soviet army's headquarters to report a system malfunction. He knew if he was wrong, the first nuclear missile attack from the US would hit within a few minutes.
Years later, he admits he was never 100% sure he was right about it being a false alarm. "Twenty-three minutes later I realised that nothing had happened. If there had been a real strike, then I would already know about it. It was such a relief," he adds.
He believes if anyone else had been working that day, they wouldn't have second guess the system like he did.
In 2014, a movie based on Petrov's actions called The Man Who Saved The World was released.
During a press interview promoting the film, Petrov said: "All that happened didn't matter to me — it was my job. I was simply doing my job, and I was the right person at the right time, that's all.
"My late wife for 10 years knew nothing about it. 'So what did you do?' she asked me. 'Nothing. I did nothing.'"