Michael Jackson spent the last night of his life rehearsing at Staples Center in Los Angeles for a series of comeback shows at London's 02 Arena set to launch next month.

TMZ reports Jackson, 50, showed up three hours late and appeared "listless" and lethargic," but his manager Frank DiLeo insists the Wednesday rehearsal was "amazing."

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"Michael rehearsed 10 or 11 songs. He sang and danced, not always at full power, but the way you do for a run-through," a sobbing DiLeo tells the Hollywood Reporter. "When the show was over, he called me, but I was in the back getting something. He found me, and said, 'Frank, I am so happy.' He said he was just so happy. He said, 'This is really our time.' He put his arm around me."

Jackson suffered cardiac arrest at his rented L.A. home the next day. He was pronounced dead at 2:26 p.m. PST.

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An autopsy is underway, though results aren't likely to be final until toxicology tests can be completed (which could take weeks). Though some reports claim Jackson may have overdosed on Demerol, Brian Oxman - who has served as the family's attorney for more than 20 years - tells Usmagazine.com he couldn't comment on the types of medications Jackson was taking.

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"It is something which is private to Michael, and we'll have to wait for the toxicology reports before we jump to any kind of conclusions," Oxman said. "I only know that I warned that his day may come. And lo and behold, here we are."

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