MJ's demise: Fans & friends devastated

King of Pop Michael Jackson's sudden death on Thursday has left his friends and fans absolutely devastated.

The 50-year-old singer is said to have died after suffering a heart attack at his home in Los Angeles.

"Like the whole world I am absolutely devastated and lost for words because everyone expected him to come to London for the concerts," Sky News quoted his friend Uri Geller, a self-proclaimed psychic, as saying.

"He was in good health, he was rehearsing, dancing, practising for the shows in England. I am shocked. I cannot -- I do not want to -- believe what I am hearing or seeing," Geller added.

Another pal and former PR representative, Jonathan Morrish, said: "I worked with him for over 25 years. It was a complete privilege." 

"I last saw him when he was last in London, which was for the World Music Awards, and he was his usual, lovely gentlemanly self. He was fine (health-wise). You don't get to the top of the tree like he did without being incredibly strong -- mentally and physically," Morrish added.

Actor Ashton Kutcher has posted a message on his Twitter blog: 'RIP. Sending love and light to family and friend but especially his kids.'

Britney Spears and Justin Timberlake also paid tribute to the King of Pop. 

The 'Toxic' hitmaker revealed that she was planning on catching one of his comeback concerts next month in London.

'I was so excited to see his show in London. We were going to be on tour in Europe at the same time and I was going to fly in to see him,' Usmagazine.com quoted Spears as saying.

'He has been an inspiration throughout my entire life and I am devastated he is gone,' she added.

Timberlake also posted a tribute to Jackson on his official website.

'I can't find the words right now to express how deeply saddened I am by Michael's passing. We have lost a genius and a true ambassador of not only Pop music but of all music,' he wrote on his website.

'He has been an inspiration to multiple generations and I will always cherish the moments I shared with him on stage and all of the things I learned about music from him and the time we spent together. My heart goes out to his family and loved ones,' he added.