Disbelief from fans greets Michael Jackson death

A Japanese fan reacts as she looks at commemorative stand for Michael Jackson at a music shop in Tokyo June 26, 2009.

LOS ANGELES (Reuters) - Michael Jackson's sudden death on Thursday was perhaps the most shocking celebrity demise since his friend Princess Diana was killed in a car crash in 1997.

As unconfirmed reports of his fatal cardiac arrest spread on the Web, disbelieving fans kept hoping for several hours that it was some sort of mistake until his death was confirmed by the Los Angeles County Coroner about 4:30 p.m. (5:30 p.m.EDT)

"Don't panic ppl! We don't know what happened! And there is not official news! These are just rumors so we can't know for sure what happened! Me or others will post as soon as I will find out anything," wrote the administrator of a Jackson fan Web site.

Some cynics initially thought that news of his hospitalization was a ploy to get out of his 50-show comeback concert series in London, scheduled to begin next month.

In a prelude to the mass gatherings that will likely happen around the world for the next few days -- recalling the outpouring of grief that greeted the passing of such icons as Princess Diana, John Lennon and Elvis Presley -- hundreds of fans gathered outside the UCLA Medical Center in west Los Angeles, where Jackson was rushed from his nearby rental home.

Some fans were crying and hugging each other, and others were climbing atop fences to get a better look at a microphone stand.

"I hope he's gone to God, and I hope that he's free of all the troubles he's been plagued with," Tonya Blazer, 50, who said she has been a fan going back to the Jackson 5.

"I just feel like I'm paying tribute to him," said Dawn Burgess, 42, a fan who said she had posters of Michael pinned to her bedroom wall when she was a child.

"To us he was a pop star. He was that to everyone. It's rude to make fun of him," said Jakquelyn Sullivan, 29, who works in the hospital's chemistry department.

Producer Quincy Jones, who worked with Jackson on his "Off The Wall," "Thriller" and "Bad" albums, said he was "absolutely devastated" by the death. "I've lost my little brother today, and part of my soul has gone with him," Jones said.

"His passing will be grieved far beyond that of any other singer, composer, producer, dancer and choreographer, in the history of the world," added Don Cornelius, the creator of the "Soul Train" TV show.

(Editing by Bob Tourtellotte)