Details are still sketchy and unconfirmed, so take everything here with a grain of salt - we'll keep you posted as we learn more.
Earlier today, Jackson was reportedly taken to the hospital in cardiac arrest after being discovered unconscious and not breathing at his home. The incident, as reported by TMZ, was apparently fatal. (Update: TMZ's source has claimed that Jackson had already passed away before paramedics arrived at his home, and they were unable to resuscitate him). Jackson, the one-time "King of Pop," had thirteen #1 hits during his music career, and had announced a major upcoming performance tour.
Again, we're waiting on independent confirmation, but if this is true, Jackson would join Charlie's Angels star Farrah Fawcett and Johnny Carson sidekick Ed McMahon as the third celebrity figure to pass away this week. It would also ironically come a day after a new mystery game was announced starring the pop musician.
Update: A second source: E! Online has a quote from a LA Fire Department spokesperson: "The call came in because a person was not breathing," said the source, who preferred to remain anonymous.
Meanwhile, Jackson's father, Joe Jackson, told E! News that the singer had had a heart attack, and that he was "...not OK."
Update #2: Jackson's death is confirmed by the LA Times: "Pop star Michael Jackson was pronounced dead by doctors this afternoon after arriving at a hospital in a deep coma, city and law enforcement sources told The Times."