Sir Elton John knew Michael Jackson was doomed as soon as he announced his mammoth run of concerts in London. The pop superstar died of an anaesthetic overdose in 2009 just weeks before he was about to start a run of 50 sell-out shows in the British capital. The Rocket Man hitmaker admits he was stunned when Jackson announced the gigs, and he is convinced the gruelling run would have killed the superstar if he had ever taken to the stage. He tells Britain's Event magazine, "The day I heard Michael was doing that, I said, 'That is never going to happen'. I knew he couldn't do it. He was a basket case. I was put out for my appendix operation with Demerol (surgical anaesthetic), and that was what Michael was taking every day - and he'd been taking it for years. "The whole thing was just utterly tragic and the idea that he went through with the tour announcement and those rehearsals... Even on a purely physical level it would have killed him." Jackson's doctor Conrad Murray is currently behind bars after he was convicted of involuntary manslaughter relating to the King of Pop's death.