tonight on "nightline," cause of death. today, the l.a. coroner released its long awaited report on how whitney houston's life ended. combination of cocaine and other drugs in her system, as he drowned in a hotel bathtub. what it tells us about her final moments. mean kids. real stories of children like yours beaten up, abused. a new documentary goes inside the world of bullies, including an outpouring of support from depp to street to gaga. and nature of the beast. he's the rogue animal lover with a knack for capping exotic creatures in the most bizarre behaviors. his radical plan to save the endangered. >> announcer: from the global

resources of abc news, with terry moran, cynthia mcfadden and bill weir in new york city, this is "nightline," march 22nd, 2012. >> good evening, i'm bill weir. drugs, jim morrison once said, are a belt with your mind. 40 years after his body was found in a bathtub, we have another belove and tortured artist to remind us of the stakes of that bet. the results of whitney houston's autopsy are in tonight, and they confirm her cocaine use and the toll that addiction took on her mind and her heart. here's abc's jim avila. >> reporter: since the day her body was pulled from the bathtub of her beverly hills suite, it is the diagnosis whitney houston's life style has warned of. and her family, friends and fans had feared. >> the final cause of death has been established as drowning, due to heart disease and cocaine

use. >> reporter: there was water in her lungs, indicating drowning. her heart weakened by 60% blockage of arteries. and the final, perhaps overriding factor, whitney houston's wlolong-time weakness cocaine contributing to her death. her body showing no indication of foul play, instead, telling medical examiners she had long abused drugs and was still using cocaine until the moment she died. >> it appeared that the cocaine had been used in the time period just probably immediately prior to her collapse. >> reporter: addiction specialist dr. drew pinsky telling "nightline" tonight, it's an outcome he has seen too often among drug users. >> when an addict dies and we know they are using, she was drinking, it's an addict death. >> reporter: photos on stained by slash, taken the night of houst houston's death, show signs of some drinking. no cocaine was found in the

suite, but dr. drew says the toxicology report paints a vivid picture of what happened that night. >> she was in severe relapse. she should not have been on a medication like xanax. that may have lead to her relapse. she should not have been drinkinging the night before. that is somebody in relapse. and somebody with a history of cocaine will inevitably get back to cocaine, which we now have evidence she did. >> reporter: it's unlikely, says dr. drew, that houston fell asleep under the influence of cocaine, a speed drug. instead, it probably caused her heart to pump too fast. >> the cocaine probably caused increase oxygen by the us manile, a coronary spasm, perhaps a clot in the artery that dissolved prior to her death so they don't see that. that, we know, can happen from cocaine. >> reporter: the houston family was informed before the coroner's office released its findings and tonight, her sister-in-law and manager pat houston issued this statement.

"we are saddened to learn of the toxicology results, although we are glad to now have closure." patricia was there when houston die and told oprah winfrey what she saw. >> i heard screams. and i saw the hair stylist drop to her knees. a woman opened her door and said, is everything all right? i said, dial 911. >>. >> reporter: but it was too late. and like many of houston's friends, she had thought the bad times were over. telling by now a weeping oprah winfrey -- >> were you always afraid of getting a phone call or hearing that this is the day that it's happened? >> if things hadn't changed. but things were changing. >> reporter: it was not her first attempt at recovery. the singer herself telling diane sawyer in 2002. >> i can't tell you it's always going to be perfect diane. >> reporter: no, everyone says it's day by day. day by day. >> yeah, yeah, yeah. >> reporter: now do you say, not

at all? >> i'm going to tell you that. i could tell you that. i am not self-destructive. i'm not a person who wants to die. i'm a person who has life and wants to live. >> reporter: houston divorced her husband, bobby brown. at the time of her death, the person closest to her, her child, bobbi kristina. she told oprah her mother was maligned and misunderstood. >> everything that everyone is safing about her, all that negativity is just -- it's garbage. >> yeah. >> that's not my mother. >> reporter: but dr. drew says it's not unusual for an addict to mislead family. and not surprising for them to deny continued drug use. >> addicts all lie. that's a feature of their disease. >> reporter: making tonight's final medical findings hard for her family and friends to hear. but buried in that autopsy report is the unavoidable

conclusion that for this great and troubled star, it was her addiction that remained her biggest enemy and her greatest love of all. for "nightline," i'm jim avila. and coming up next, how the bully down your block has new enemies in the likes of justin bieber and meryl streep. ♪ [ male announcer ] how could switchgrass in argentina, change engineering in dubai, aluminum production in south africa, and the aerospace industry in the u.s.? at t. rowe price, we understand the connections of a complex, global economy. it's just one reason over 75% of our mutual funds beat their 10-year lipper average. t. rowe price. invest with confidence. request a prospectus or summary prospectus with investment information, risks, fees and expenses to read and consider carefully before investing.

with investment information, risks, fees and expenses when bp made a commitment to the gulf, we knew it would take time, but we were determined to see it through. today, while our work continues, i want to update you on the progress: bp has set aside 20 billion dollars to fund economic and environmental recovery. we're paying for all spill- related clean-up costs. and we've established a 500 million dollar fund so independent scientists can study the gulf's wildlife and environment for ten years. thousands of environmental samples from across the gulf have been analyzed by independent labs under the direction of the us coast guard. i'm glad to report all beaches and waters are open for everyone to enjoy. and the economy is showing progress with many areas on the gulf coast having their best tourism seasons in years. i was born here, i'm still here and so is bp.

we're committed to the gulf for everyone who loves it, and everyone who calls it home. greetings from the people here sure are friendly but some have had a hard time understanding my accent. so to make sure people get every word of the geico savings message i've been practicing how to talk like a true chicagoan. switching to geico could save you hundreds of dollars on car insurance... da bears. haha... you people sure do talk funny. geico®. fifteen minutes could save you fifteen percent or more on car insurance. ooh gas. take an antacid. oh thanks. good luck. good luck to you. doesn't he know antacids won't help gas? oh, he knows. [ male announcer ] antacids don't relieve gas. gas-x is designed to relieve gas. gas-x. the gas xperts.

>> announcer: "nightline" continues from new york city with bill weir. the play ground bully is a hollywood show we've seen a million times. two acts worth of wedgies, a redeckive come up ants at the end. in the end, victims can carry life long scars. ironic that it took a movie made well outside of hollywood to

muster that town's, and the nation's attention. here's my co-anchor terry moran. ♪ i was born this way >> reporter: behind her power pop music and far out fashion, lady gaga is a passionate and serious crusader, frankly talking about a huge issue for millions of young americans. bullies. >> i am going to be working as harold also i can to make bullying a hate crime. >> reporter: the torment of bullying has wounded generations of people, as meryl streep recalled this week. >> this one bully was hitting my legs with a stick until they bled. >> reporter: streep spoke at a manhattan screening for a powerful new movie called, simply, "bully." at the heart of the movie is the story of a 15-year-old boy, alex, who is emerging as one of the heroes of the anti-bullying molt. >> most kids don't want to be

around me. i feel like i belong somewhere else. >> reporter: by word of mouth and soerl media and a big hollywood studio push, "bully" has become a movie. >> they punch me in the jaw, strangle me, take things from me. they push me so far that i want to become the bully. >> reporter: this is a movie that takes you inside the real world of bullies, their victims and the adults who somehow can't seem to stop it. >> they are stabbing him with pencils and choking him and, you know -- >> i wish i could say i could make it stop. i'm not going to lie to you. i can't. >> reporter: the film opens an astonishing window into the lives of millimeters of kids, 13 million a year, according to one, who are relentlessly demeaned and physically attacked in our schools every single day. >> i was bullied also a kid. >> reporter: lee is the director who made "bully." it's deeply personal for him. >> i want to introduce you guys

to alex. kids that go through bullying are like the unsung heroes because they are so strong. >> no, no -- ow. >> reporter: three years ago, when lee showed up with his cameras in iowa, things were tough for alex. real tough. >> bullying can be akin to torture. and we don't tolerate that. and so we ought not in these situations. >> reporter: one of the things you want to do with this movie is break the silence and start a kind of revolution for the kids who are being bullied. >> amen. >> the boy committed suicide last week. >> reporter: but for some kid is, for far too many, it is too late for that. a 15-year-old girl in massachusetts. a 17-year-old boy in georgia. tyler long, who killed himself in 2009. >> i cut the belt off his neck, let him down. we checked to see if he was still alive.

it was too late. >> reporter: abc's "20/20" met the longs a year after tyler's death. his mom, tina, says he just couldn't take the abuse at school anymore. >> he was such an easy soul. e he never could understand why. he didn't get it. >> reporter: the longs have gone from grieving to leading the fight against bullies and the movie recounts their journey. >> my voice is not going to fall silent. i will go to my grave until a difference is made. >> reporter: does it help, the work you're doing now? does it help deal with the pain and the loss? >> oh, yeah. >> it does. i don't think the pain will ever go away, but it gives you -- it gives you hope. >> reporter: and that's the message of bullying. there is hope. it's a perfect message for kids, but the movie's been rated r for

the use of bad language. that means the kids who could get the most from this film can't see it without an adult. enter katie butler. >> we're missing the entire target audience. >> reporter: katie, 17 years old and a bullying survivor herself decided to fight the motion picture association of america, which gave the movie its r rating. >> middle school and high school students need to see this movie, will have a really hard time receiving it because of that r rating. i went on change.org and signed a petition to change the rating. >> reporter: so far, more than 450,000 people have signed the petition, including johnny depp, justin bieber, kelly ripa. >> it should be mandatory viewing for all kids going into middle school. >> reporter: and ellen degeneres. >> i have signed it, i hope you will, too. >> reporter: as of now, the rating for "bully" is unchanged. we joined alex, lee and the longs, the people who are apart of "bully" for a screening in

washington, d.c. for them, and for so many others, they want this moment to be a call to action. >> i think our young people are finally saying, enough is enough. and that's what it's going to take to change the culture and the climate. >> reporter: a dream? maybe. but alex's journey out of the darkness of our bullying culture is one we can all make. he'll lead the way. when people ask you for advice, does it make you feel good? proud? >> yeah, i feel like i'm the teacher. i feel like i'm actually teaching them to -- how to make the world a better place. >> reporter: and as they say, things do get better. >> alex's school district says since filming, they have new policies including increased cameras on buses and they allowed the filmmakers in to increase the discourse. and coming in, the man at the center of the famous rutgers

bullying trial. dharun ravi was just convicted of a hate crime. >> do you hate gay people? >> i don't hate gay people. >> do you fear gay people? >> no. >> do you want want to be around gay people? >> it doesn't matter to me at all. >> do you believe tyler clementi was intimidated by you? >> he knew i wasn't trying to imtim dai imintimidate him. >> you feel confident of that? >> i do. >> chris coe mope's interview will hair tomorrow on "20/20." coming up, the world's most exotic animals and the man out to save them in the most controversial ways.

wow. this is new. yep, i'm sending the dancing chicken to every store in the franchise to get the word out. that could work. or you could use every door direct mail from the postal service. it'll help you and all your franchisees find the customers that matter most -- the ones in the neighborhood. you print it or we'll help you find a local partner. great. keep it moving, honey. honey? that's my wife. wow. there you go. there you go. [ male announcer ] go online to reach every home, every address, every time with every door direct mail. multi-policy discount. paperless discount. paid-in-full discount. [yawning] homeowner's discount. safe driver discount. chipmunk family reunion.

someone stole the nuts. squirrel jail. justice! countless discounts. now that's progressive. call or click today.

as i learned on our recent trip to africa, there are only a

few places on the planet where you can find african lions and asian tigers living side by side. zoos, the circus and one man's radical experiment in conservation. when on safari, it's usually the four-legged creatures that provide the most entertainment. but in this corner of south africa, it is often a two-legged creature named john varty. >> my reichel ifle in the momen the back of the vehicle. this is too clumsy to hold. i'm relying just on my knowledge of the situation. >> reporter: he's known as j.v. around here. and in the world of conservation and wild life photography, he's known as one of the most stroern y'all characters. >> i'm not a good cameraman. ill rely on technology. but all i have -- i have a great passion for what i do. >> reporter: since his family has long owned a luxurious private game reserve, he grew up around some of the most

magnificent beasts on the planet. over the years, he's captured some amazing samples of their behavior. like the time a mother cape buffalo stalked the leopard that had taken her calf. it is just part of nat geo wild's "caught in the act," which treats us to a moon goose fighting a lion. and an overly excited young elephant, trying to mate with a rhino. and it including john varty's rare glimpse of a mother leopard taking on the pie thor that swallowed her cub. she forces the snake to rejudge talt the newborn. and in an ending rarely seen in these, the mother burr rips part of the cub and eements the rest. >> what was most amazing, that night, she stood on top of this rock and she called for the cub. three days later, she finally

left these rocks and moved off, with no cub. >> reporter: wow. we don't want to project human emotions, but that was some sort of grieving process. you believe that was the case? >> absolutely. >> reporter: some buy yol jilss might take issue with that, and plenty find fault with his flair. but varty's caught the most heat on his ideas of how to save endangered species, like the tiger. varty wants to actually move tigers from the jungles of asia to his land in africa. >> there she goes. there's a -- ah. >> reporter: encouraging them to hunt strange new prey. all the while, composing a musical in their honor. ♪ no more freezing cages ♪ no more insanity >> reporter: one famed conservationist tells me it makes as much sense as

introducing grizzly bears to the everglades. no less controversial is his plan to save endangered rye knows. poachers slaughter hundreds each year in order to chain saw off the horns and sell them for more than 100,000 bucks a i piece on the asian black market. >> the horn is believed to be an after roe deese yak. and today, it fetches more than gold per ounce. >> reporter: while trading is strictly forbidden. varty wants to legalize the trade, so they can harvest and use the profits for conversation. >> the rye nore would still be alive. >> reporter: so far, the ideas have received more scorn than acceptance. >> i had the engine running. i was moving quickly. >> reporter: but like all the encounters out here, j.v., angry resistance is just another part of nature.