Michael Jackson's death dominated news bulletins, radio airwaves and social networking sites the world over on Friday as tributes poured in for a man called the King of Pop and natural heir to Elvis.

The 50-year-old, whose towering musical legacy was tarnished by often bizarre behavior and sex scandals, was pronounced dead at 2:26 p.m. PDT (2126 GMT) on Thursday after arriving at a Los Angeles hospital in full cardiac arrest.

King of pop is dead. Black day for music, was the simple message left by johnyvergosa on the Twitter messaging site, where Jackson accounted for four of the five top topics. Actress Farrah Fawcett, who also died on Thursday, was the fifth.

Other online contributors expressed disbelief at the suddenness of Jackson's death, less than three weeks before he was due to launch a series of comeback concerts in London.

The singer's lasting appeal, despite life as a virtual recluse since his acquittal of child abuse charges at a 2005 trial, was underlined when 750,000 fans of all ages snapped up tickets for the sellout gigs.

From Thriller to Billie Jean and Rock With You to The Way You Make Me Feel, Jackson's hits filled the airwaves.

Local politics and global affairs were bumped off the front pages of newspapers, trading rooms were abuzz with the news and entertainment websites saw a surge in traffic.

The King of Pop is Dead read the main headline of Britain's Independent newspaper, below a full-page portrait.

Rina Masaoka, a 21-year-old college student in Japan, said: This will probably be as shocking as Princess Diana's death.

Ray Cordeiro, an octogenarian radio disc jockey in Hong Kong who has been on air for around half a century, called Jackson a genius and a legend in our lifetime.

Former Beatle Paul McCartney said in a statement: It's so sad and shocking. I feel privileged to have hung out and worked with Michael. He was a massively talented boy man with a gentle soul. His music will be remembered forever.

FLAWED GENIUS

Commentators reflecting on Jackson's life focused on his flaws as well as his global fame and musical flair.

Broken and broke: the child star haunted by fame and scandal read a profile in the Guardian newspaper, which called him the natural successor to Frank Sinatra and Elvis Presley.

Jackson sold an estimated 750 million records, a figure that is likely to rise with the expected posthumous re-release of his hits. Thriller, which came out in 1982, remains the best-selling album of all time.

Jackson also won 13 Grammy Awards, made boundary-breaking music videos and his slick dance moves were imitated by legions of fans, and fellow pop stars, around the world.

But his preference for the company of children, high-pitched voice, numerous plastic surgeries and life as a virtual recluse earned him many critics and the nickname Wacko Jacko.

When he came to London to announce his residency at the O2 Arena starting on July 13, bookmakers immediately took bets on whether he would turn up for the first show, amid concerns and rumors over his physical and mental health.

His sudden death, nevertheless, came as a surprise.

I spoke to Michael only a few days ago and he was absolutely on top of everything, working hard and really excited about (the) forthcoming shows, said Mark Lester, a former child actor and godfather to Jackson's children.

Quincy Jones, who worked closely with Jackson on some of his most successful recordings, led tributes from the music world.

I am absolutely devastated at this tragic and unexpected news, he said of one of the first black entertainers of the MTV generation to gain a big crossover following.

Pop star Madonna said: I can't stop crying over the sad news ... I have always admired Michael Jackson. The world has lost one of the greats but his music will live on forever.

Germany's Economy Minister Karl-Theodor zu Guttenberg, speaking in front of the Adlon Hotel where in 2002 Jackson caused a stir by dangling his baby from a top floor window in front of adoring fans, described Jackson as a great artist.

But his life was also rather tragic in the end ... That's why I hope his whole life is taken into account when reflecting upon his death and not only the last few years.

More on Michael Jackson:

Michael Jackson to Lisa Marie: 'I am afraid I am going to end up like Elvis Presley’

Family and friends speak on Michael Jackson death

‘May Allah be with you’: Jermaine Jackson on brother’s death (VIDEO)