A former Soviet military officer credited with averting a possible nuclear disaster at the peak of the Cold War has died at the age of 77.
Stanislav Petrov was on duty at a Russian nuclear early warning centre in 1983 when computers wrongly detected incoming missiles from the US.
He took the decision that they were a false alarm and did not report them to his superiors.
His actions, which came to light years later, possibly prevented nuclear war.
Petrov died at his home in Moscow in May but his death has only now been made public.
In an interview with the BBC in 2013, Petrov told how he had received computer readouts in the early hours of the morning of 26 September 1983 suggesting several US missiles had been launched.
"I had all the data [to suggest there was an ongoing missile attack]. If I had sent my report up the chain of command, nobody would have said a word against it," he said.
"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."
Although his training dictated he should contact the Soviet military immediately, Petrov instead called the duty officer at army headquarters and reported a system malfunction.
If he had been wrong, the first nuclear blasts would have happened minutes later.
"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 recalled.
A later investigation concluded that Soviet satellites had mistakenly identified sunlight reflecting on clouds as the engines of intercontinental ballistic missiles.
Petrov, who retired with the rank of lieutenant colonel, died on 19 May but news of his passing became widely known only this month, thanks to a chance phone call.
German film-maker Karl Schumacher, who first brought Petrov's story to an international audience, telephoned him to wish him a happy birthday on 7 September only to be informed by his son, Dmitry Petrov, that he had passed away.
Mr Schumacher announced the death online and it was eventually picked up by media outlets.