It was September 26, 1975, nearly dawn on the moonlit crags of Everest. Mountaineer Nick Estcourt, of the Boningtoo expedition, struggled up the ropes that linked Camps 4 and 5. As he reached 300 metres about camp 4, he saw a figure climbing after him. He could just make out the dark limbs against the bright snow. It looked as though another climber had set out earlier than planned. When he telephoned from camp 5, Estcourt was told that no one had left camp 4. Later that day, Mick Burke, a television cameraman with the team, died in a lone climb to the summit of Everest. When Chris Bonington, the leader of the expedition, returned to Britain, he was handed a strange letter. It had been written early in 1975 by a clairvoyant named Clement Williamson, and then locked in a bank vault for safe keeping. It contained a message Williamson had recieved from a climber named Andrew Irvine, who had disappeared on Mount Everest in 1924. The message proficted that no the Bonington expedition a ghost would appear and that someone would die.
but what actually was the cause, it remained a mystery? 
is it really tru ?