On the morning of June 19, Leonardo DiCaprio stood in the open hatchway of a plane flying 12,500 feet above the Southern California desert--then took a leap. The actor was "tandem jumping"--skydiving with an instructor--as part of a birthday celebration for his friend, actor Justin Herwick. Right on cue, at 5,000 feet above the ground, DiCaprio yanked the rip cord. The chute failed--and DiCaprio panicked. "It didn't open properly," says the instructor, Harley Powell, who delayed opening his own chute and spent about 25 frantic seconds trying to fix DiCaprio's as they fell earthward. Finally--to his pupil's great relief--Powell released DiCaprio's emergency back-up chute, averting disaster. Says Herwick: "Ithought I was going to lose my best friend."

The point of that story, say DiCaprio's pals, is that the 22-year-old star of William Shakespeare's Romeo & Juliet is, ultimately, not as bent on self-destruction as the press sometimes makes him out to be. In a pinch, he wanted to remain in one glorious piece--something not everyone would have predicted. Indeed in 1994, citing his club-hopping ways, Rolling Stone noted ominously that DiCaprio "seems poised to assume the mantle of River Phoenix." Nonsense, say DiCaprio's defenders. There's "nothing River Phoenixy" about him, insists photographer Patrick McMullan "He likes to party, but he isn't caught up in it." Adds screenwriter James Toback (Bugsy): "He's a very cunning, calculating, shrewd and smart guy. He would run away from anybody and anything that might sabotage him. He does not want to fail."

If DiCaprio is trying to fail, he's making a terrible job of it. Hard on the heels of Romeo, he returns to the screen on Dec. 18 in Marvin's Room, a family drama featuring Meryl Streep, Robert De Niro and Diane Keaton. And right now, in Rosarito, Mexico, DiCaprio is shooting Titanic, a $150 million epic, due out next summer, co-starring Sense and Sensibility's Kate Winslet. Why would an actor who works so hard have to fend off so many rumors about dangerous habits? "Scandal sells," DiCaprio told The New York Times in 1995. "If you hear of any incident about me--a fight, a change of clothes, a little extra gel in the hair, don't believe it till you talk to me."

Of course, pinning him down for a chat is no easy feat. DiCaprio declined to be interviewed for this story, and the record shows he doesn't particularly care about fending off rumors about himself. He may, in fact, even enjoy being preceded by a naughty rep. "Fame is not the worst thing," he told the Vancouver Sun in October. "I went to dinner the other night, and the girls in the restaurant ignored me. It was so annoying."

Friends and colleagues say that the real Leonardo is a lot less intimidating than the myth. Romeo coproducer Martin Brown agrees. Before filming began last spring in Mexico City, he says, "we thought we'd better have some bail money set aside. But it went much better than we expected." Nor was there sexual tension between DiCaprio and his Juliet, Claire Danes. "He's truly brilliant," says Danes, 17, "but I don't think we could be together romantically. We became close with the work, but we were never buddies." DiCaprio has said recently he was involved in a yearlong relationship with a woman not in show business. But at the premiere of Romeo, he showed up with model Kristin Zang. "Leonardo," says Toback, "is always with one girl or another."

Not bad for someone who until last year was living with his mother, Irmelin, in East Hollywood. Even now the L.A. bungalow he shares with his pet bearded dragon lizard isn't far from either parent. Irmelin, a German-born former legal secretary, and Leo's father, George, a self-described "old hippie" who worked as an underground comic-book artist and distributor, divorced when their son was 1 but remain close and help manage his booming career.

DiCaprio's parents once thought he might follow a different path--that of his namesake, the other Leonardo. "When I was pregnant," says Irmelin, "George and I were in a museum looking at a painting by da Vinci. The baby started kicking--we thought it was a sign." For a while, it was. Growing up in a tough section of Hollywood, Leonardo loved painting. Even more, he enjoyed mimicry--though his father wishes Leonardo hadn't done such a wicked Charles Manson one day in junior high school. Leonardo's teachers were "really alarmed," says George. "I had to explain that it was an imitation."

In high school, DiCaprio decided to imitate Adam Farrar, his older stepbrother, who had appeared in commercials. DiCaprio signed at 14 with an agent and did a spot for Matchbox cars, and in 1991 he landed a role on Growing Pains as Luke, a homeless boy. By then he had the bug. High school was completed with a tutor; college was put off. "Life," he told The San Francisco Examiner, "is my college for now."

DiCaprio's breakthrough came when he beat out hundreds of actors for the role of Robert De Niro's abused stepson in 1993's This Boy's Life. At 19 he earned an Oscar nomination for his portrayal of a retarded teenager in What's Eating Gilbert Grape,thenwon raves for The Quick and the Dead and The Basketball Diaries. For Marvin's Room De Niro handpicked DiCaprio, who went on to impress his costars. "He's always compelling," says Streep. "You can't watch anything else when he's acting. "

Such accolades apparently haven't gone to his head. "He's the most down-to-earth person I've met," says Diaries costar Mark Wahlberg. "Very un-Hollywood." On the Romeo set, jokes Danes, "he did cartwheels and hit people over the head with Twizzlers."

Not the sort of thing Cary Grant did during Holiday, perhaps, but no one is complaining. Romeo and Juliet has grossed over $35 million so far, and DiCaprio, says costar John Leguizamo, is "the new `It'. " Adds producer Brown: "At a preview screening in L.A., there were gasps from the audience when Leo came onscreen. There were, like, squeals." He searches for an analogy. "It was," he says finally, "l