HE WAS SO many things to so many people, a man of many nicknames - from the "King of Pop" to "Wacko Jacko" - and even more faces.

A child star, a fashion icon, a spell-binding entertainer who seemed to walk on the Moon and finally a bizarro-world Elvis who finally spun his own disturbing version of the time-worn story of superstar decline - Michael Jackson was all of these and more.

But to a generation of millions at the end of the great American Baby Boom, born just a tad too late to experience the upheaval of the 1960s, he was not just any rock star but the first pop icon that truly belonged to them, one whose youthful energy once mirrored their own.

Which is why the news of Jackson's sudden death at age 50 yesterday hit so many people with all the pop-cultural impact of one of the singer's trademark mid-song shrieks.

"I think we'll mourn his loss as well as the loss of ourselves as children listening to 'Thriller' on the record player," the rock star John Mayer wrote on the social networking site Twitter, which erupted with reactions amid the first sketchy reports that Jackson had collapsed midday at his mansion in the Bel-Air section of Los Angeles, near Sunset Boulevard.

Jackson was not breathing when Los Angeles Fire Department paramedics responded to a call there at 12:30 p.m. Pacific time, Capt. Steve Ruda told the Los Angeles Times. He was apparently in cardiac arrest, and the paramedics performed CPR and took him to UCLA Medical Center, Ruda told the newspaper.

According to CBS News, the paramedics tried to resuscitate Jackson - described in an initial bulletin as a "50 year old male, not breathing at all" - for 42 minutes.

A large crowd gathered outside the medical center on the western side of Los Angeles, where fans reportedly shouted, "You've got to save him! You've got to save him!"

Jackson - whose frequent rounds of plastic surgery, some of which were linked to later health problems, were a keystone of his increasingly bizarre persona - had been dogged by recent rumors of illness and frailty.

But, at the same time, he also seemed poised for a long-awaited comeback: Some 800,000 tickets were snapped up in minutes for a series of 50 concerts that he had planned beginning in July at London's O2 Arena, even as some doubted the 50-year-old icon would be healthy enough to perform. According to the Hollywood Reporter, Jackson had rehearsed his show at a Los Angeles arena on Wednesday night.

Today, the London tickets are collectors' items.

Although his life was cut all too short, Michael Joseph Jackson still managed to span two centuries, epitomized in 2009 by the bouncing electrons that first announced his death on an Internet site, TMZ.com, and that mourned him on social-networking sites.

"Ladies and gentlemen, Michael Jackson has just died," a woman boarding a Manhattan bus called out, shortly after the news was announced. Immediately, many riders reached for their cell phones.

But Jackson was truly a child of the Industrial Revolution, the seventh of nine children, born in 1958 to a Gary, Ind., steel worker and his wife. His first record - with four of his brothers in Motown's proto-boy-band, the Jackson 5 - was the bouncy "I Want You Back," released in October 1969, just six weeks after the mucky madness of Woodstock.

The Jackson 5, producers of classic bubblegum No. 1 hits like "ABC" and "I'll Be There," quickly became the voice of adolescent rear-guard Baby Boomers seeking something different from the flower-power of their older siblings.

"The Jackson 5 when Michael was there was as big as the Beatles and created the same amount of pandemonium," legendary Philadelphia disc jock Jerry Blavat said last night, adding that "he was the most talented performer at 13 or 14 that I had ever seen in my life."

But young success merely set the stage for the 1980s, when Jackson, by then largely a solo act, defined a style for a new video era that was exploding on MTV. He did so with outrageous costumes puncuated by one white glove, a mesmerizing performance style that mixed gliding "moonwalks" with sudden shrieks and crotch grabs, and with a monster record, "Thriller," that sold more than 100 million copies, according to some estimates.

Yet, as the years passed, there was clearly something strange, sad even, about Jackson, whose claims that celebrity and an abusive father had robbed him of his youth came as he spent millions on the childlike world of his Neverland Ranch, in Southern California, filled with amusement park rides and zoo animals.

His frequent surgeries and medical issues that lightened his skin color and seemed to diminish his other African-American features clearly troubled some fans, and his intermittent records typically sold worse than the ones before, even as publicists branded him "The King of Pop."

Indeed, Jackson's brief marriage to Elvis Presley's only daughter, Lisa Marie, cemented his place in pop royalty. Eventually, Jackson married twice and had three children - the third one by artificial insemination with a surrogate mother - but he would be increasingly dogged by speculation over his close friendships with young boys.

Twice, the allegations bubbled over into the legal system and nearly destroyed Jackson's career. In 1994 he paid $22 million to the family of a 13-year-old boy who'd reportedly made sexual allegations. Later, California authorities launched an investigation and eventually indicted Jackson over allegations involving a 14-year-old boy, but the singer was acquitted after high-profile trial in 2005.

But his legal fights led to some highly publicized money woes, and Jackson appeared increasingly frail - his child-like voice even softer than usual - the rare times he appeared in public. But the Los Angeles Times said that Jackson reportedly passed a health screening last month, as he stepped up the pace of rehearsals for the London gi

To the end, many preferred to remember

Jackson as the young and dynamic performer he was in the 1970s and 1980s.

"He was a very kind person, extremely shy," said author and musician James McBride, who spent several months covering Jackson's "Victory Tour" for People magazine in the 1980s. "He felt wary of the press, he felt put upon and misunderstood by the press."

But many people not only understood but felt the cultural impact of Michael Jackson right to the very end.

"No joke. King of Pop is no more. Wow," Michael Harris, 36, of New York City, read from a text message a friend sent to his telephone. "It's like when Kennedy was assassinated. I will always remember being in Times Square when Michael Jackson died." *

Staff writer Dan Gross and the Associated Press contributed to this report.