Los Angeles (AP) - Authorities are seeking to clear up the mystery surrounding Michael Jackson's death, including whether prescription drugs could have been a factor.
An autopsy was planned for Friday, though results weren't likely to be final until toxicology tests could be completed, a process that could take several days and sometimes weeks. However, if a cause can be determined by the autopsy, they will announce the results, said Los Angeles County Coroner Investigator Jerry McKibben.
Police said they were investigating, standard procedure in high-profile cases.
Brian Oxman, a former attorney of Jackson's and a family friend, said he was concerned about Jackson's use of painkillers and he warned the singer's family about possible abuse.
"I said one day, we're going to have this experience. And when Anna Nicole Smith passed away, I said we cannot have this kind of thing with Michael Jackson," Oxman said Friday on NBC's "Today" show. "The result was, I warned everyone, and lo and behold, here we are. I don't know what caused his death. But I feared this day, and here we are."
The 50-year-old musical superstar died Thursday, just as he was preparing for a series of 50 concerts starting July 13 at London's 02 arena.
He died at UCLA Medical Center after being stricken at his rented home in the posh Los Angeles neighborhood of Holmby Hills. Paramedics tried to resuscitate him for nearly three-quarters of an hour, then rushed him to the hospital, where doctors continued to work on him.
His brother Jermaine said it was believed that Jackson suffered cardiac arrest at his home. Cardiac arrest is an abnormal heart rhythm that stops the heart from pumping blood to the body. It can occur after a heart attack or be caused by other heart problems.
A handful of bleary-eyed fans camped out throughout the night with media outside the Jackson family house in the San Fernando Valley and near his star on the Hollywood Walk of Fame. People heading to work in New York on Friday were stopping at a makeshift memorial outside Harlem's Apollo Theater, where Jackson performed as a child.
Oxman, who said he was speaking on behalf of no one but himself, and other friends made the rounds among the news outlets Friday, adding to the intrigue of Jackson's early demise. Oxman claims Jackson had prescription drugs at his disposal to help with pain suffered when he broke his leg after he fell off a stage and for broken vertebrae in his back.
"When the autopsy comes, all hell's going to break loose, so thank God we're celebrating him now," Liza Minnelli told CBS' "The Early Show" by telephone.
In 2007, Jackson settled a lawsuit filed by a Beverly Hills pharmacy that claimed he owed more than $100,000 for prescription drugs over a two-year period.
After Jackson was acquitted on child molestation charges in 2005, Santa Barbara County District Attorney Tom Sneddon argued against returning some items belonging to Jackson he labeled "contraband." Sneddon said those included syringes, the drug Demerol and prescriptions for various drugs, mainly antibiotics, that were in different people's names.
Stephen Hill, an executive producer for the BET Awards, said Sunday's show would be dedicated to Jackson because of his influence on music and pop culture.
"I think what you're going to find is that acceptance speeches for awards will have nothing to do about the artists themselves, but about the influence that Michael Jackson had on them," Hill said in a phone interview.
Jackson's death brought a tragic end to a long, bizarre, sometimes farcical decline from his peak in the 1980s, when he was popular music's premier all-around performer, a uniter of black and white music who shattered the race barrier on MTV, dominated the charts and dazzled even more on stage.
His 1982 album, "Thriller" - which included the blockbuster hits "Beat It," "Billie Jean" and "Thriller" - is the best-selling album of all time worldwide.
Yet after selling more than 61 million albums in the U.S. and having a decade-long attraction open at Disney theme parks, Jackson died reportedly awash in about $400 million in debt, on the cusp of a final comeback after well over a decade of scandal.
As word of his death spread, MTV switched its programming to play videos from Jackson's heyday. Radio stations began playing marathons of his hits. Hundreds of people gathered outside the hospital. In New York's Times Square, a low groan went up in the crowd when a screen flashed that Jackson had died, and people began relaying the news to friends by cell phone.
The public first knew him as a boy in the late 1960s, when he was the precocious, spinning lead singer of the Jackson 5, the singing group he formed with his four older brothers out of Gary, Ind. Among their No. 1 hits were "I Want You Back," "ABC" and "I'll Be There."
He was perhaps the most exciting performer of his generation, known for his backward-gliding moonwalk, his feverish, crotch-grabbing dance moves and his high-pitched singing, punctuated with squeals and titters. His single sequined glove, tight, military-style jacket and aviator sunglasses were trademarks, as was his ever-changing, surgically altered appearance.
"For Michael to be taken away from us so suddenly at such a young age, I just don't have the words," said Quincy Jones, who produced "Thriller." "He was the consummate entertainer and his contributions and legacy will be felt upon the world forever. I've lost my little brother today, and part of my soul has gone with him."
Jackson ranked alongside Elvis Presley and the Beatles as the biggest pop sensations of all time. He united two of music's biggest names when he was briefly married to Presley's daughter, Lisa Marie. Jackson's sudden death immediately evoked comparisons to that of Presley himself, who died at age 42 in 1977.
"I am so very sad and confused with every emotion possible," Lisa Marie Presley said in a statement. "I am heartbroken for his children who I know were everything to him and for his family. This is such a massive loss on so many levels, words fail me."
As years went by, Jackson became an increasingly freakish figure - a middle-aged man-child weirdly out of touch with grown-up life. His skin became lighter, his nose narrower, and he spoke in a breathy, girlish voice. He often wore a germ mask while traveling, kept a pet chimpanzee named Bubbles as one of his closest companions and surrounded himself with children at his Neverland ranch, a storybook playland filled with toys, rides and animals. The tabloids dubbed him "Wacko Jacko."
Jackson caused a furor in 2002 when he playfully dangled his infant son, Prince Michael II, over a hotel balcony in Berlin while a throng of fans watched from below.
In 2005, he was cleared of charges that he molested a 13-year-old cancer survivor at Neverland in 2003. He had been accused of plying the boy with alcohol and groping him, and of engaging in strange and inappropriate behavior with other children.
The case followed years of rumors about Jackson and young boys. In a TV documentary, he acknowledged sharing his bed with children, a practice he described as sweet and not at all sexual.
Despite the acquittal, the lurid allegations that came out in court took a fearsome toll on his career and image, and he fell into serious financial trouble.
Michael Joseph Jackson was born Aug. 29, 1958, in Gary. He was 4 years old when he began singing with his brothers - Marlon, Jermaine, Jackie and Tito - in the Jackson 5. After his early success with bubblegum soul, he struck out on his own, generating innovative, explosive, unstoppable music.
The album "Thriller" mixed the dark, serpentine bass and drums and synthesizer approach of "Billie Jean," the grinding Eddie Van Halen guitar solo on "Beat It" and the hiccups and falsettos on "Wanna Be Startin' Somethin'."
The peak may have come in 1983, when Motown celebrated its 25th anniversary with an all-star televised concert and Jackson moonwalked off with the show, joining his brothers for a medley of old hits and then leaving them behind with a pointing, crouching, high-kicking, splay-footed, crotch-grabbing run through "Billie Jean."
The audience stood and roared. Jackson raised his fist.
During production of a 1984 Pepsi commercial, Jackson's scalp sustained burns when an explosion set his hair on fire.
He had strong follow-up albums with 1987's "Bad" and 1991's "Dangerous," but his career began to collapse in 1993 after he was accused of molesting a boy who often stayed at his home. The singer denied any wrongdoing, reached a settlement with the boy's family, reported to be $20 million, and criminal charges were never filed.
Jackson expressed anger over the allegations on the 1995 album, "HIStory," which sold more than 2.4 million copies, but by then, the popularity of Jackson's music was clearly waning even as public fascination with his increasingly erratic behavior was growing.
Jackson married Lisa Marie Presley in 1994, and they divorced in 1996. Later that year, Jackson married Deborah Rowe, a former nurse for his dermatologist. They had two children together: Michael Joseph Jackson Jr., known as Prince Michael, now 12; and Paris Michael Katherine Jackson, 11. Rowe filed for divorce in 1999.
Jackson also had a third child, Prince Michael II, now 7. Jackson said the boy, nicknamed Blanket as a baby, was his biological child born from a surrogate mother.
Billboard magazine editorial director Bill Werde said Jackson's star power was unmatched. "The world just lost the biggest pop star in history, no matter how you cut it," Werde said. "He's literally the king of pop."
Jackson's 13 No. 1 one hits on the Billboard charts put him behind only Presley, the Beatles and Mariah Carey, Werde said.
"He was on the eve of potentially redeeming his career a little bit," he said. "People might have started to think of him again in a different light."
Authorities are seeking to clear up the mystery surrounding Michael Jackson's death, including whether prescription drugs could have been a factor.