Exclusive details about the bands private dynamic. And a lesson from the master on the bands famous crab pole im a 43yearold man in tight jeans, im not sure this is going to happen. First the nightline 5. We enjoy life by enjoying it. Boost simply complete. Made with nine ingredients, 25 vitamins and the minerals, 10 grams of protein. Boost, be up for it. Moms got this cold. Stuffy nose, no sleep, mouth breather. Just put on a breathe right strip. It instantly opens your nose up to 38 more than Cold Medicine alone. Shut your mouth and say good night, mouth breathers. Breathe right. Number one in just 60 seconds. Why are you checking just want to see if it changed. Credit scores dont change that much do they . Really . Ill take it sir, your credit. I better check my credit score. Try credit karma. Its free. Alright. Check out credit karma today. Good evening. Thanks for joining us. We begin with breaking news. Donald Trumps National security adviser Michael Flynn has resigned tonight, just one month into his tenure, amid growing concerns about his contact with the Russian Ambassador and whether he misled Vice President pence about whether sanctions against russia were discussed. Flynn wrote in his resignation letter, unfortunately because of the fast pace of events i inadvertently briefed the Vice President elect and others with incomplete information regarding my phone calls with the Russian Ambassador. The retired Lieutenant General added i have sincerely apologized to the president and Vice President and they have accepted my apology. Well have a complete wrapup on Good Morning America tomorrow. A tragic story, were hearing from the parents of the boy killed on that extreme water slide billed as the worlds largest. Their emotional and candid account of the unimaginable. Matt gutman sat down with the family who has a message for us all. Reporter on the schwabs went to the worlds tallest water slide, admission was free for the families of state legislators. But that thrill ride would cost the kansas state let gislator a his wife most dear. Six went to the park and five came back. Reporter for the first time scott and Michelle Schwab recount that tortured sunday. Hoping that sharing their story will help keep calebs memory alive. I still remember him sitting on the floor, were going to go to the park he lit up, so excited. Reporter the schwabs piled their four boys, including 10yearold caleb, into the car. They had a nickname for their second son. Called him monkey bear because he climbed everything. He would hug like a bear. Hes 10 years old, he still wraps his arms and legs around you for a hug. Reporter he was that kind of brother. You see him here dancing with his baby brother isaac. When they got to the park, caleb and his 12yearold brother nathan went right to the 170foot scaffold of verruct, which means insane in german, billed as an extreme thrill ride. I said, brothers stick together. He says, i know, dad. Reporter it was the last time his parents would see caleb alive. Big brother nathan was dutifully waiting for him at the bottom when the unimaginable happened. He was screaming. He flew from verrukt. Reporter nathan ran to find his mother but the horror made it nearly impossible for the 12yearold to explain. There was a gentleman who wouldnt allow me to come close enough to see what was going on. He just kept saying, no, trust me, you dont want to go any further. Reporter scott was in such shock, Good Samaritans had to confirm the incomprehensible. I need to hear you say it, is my son dead . He said, yes, your son i put us on a golf cart, sorry you lost your son. It was surreal. I hardly remember driving home. Reporter so far no criminal charges have been filed, but the family has settled with the theme park for an undisclosed sum which will go to calebs three brothers. The family is still pursuing legal action against others including the firm contracted to build the slide. They declined our request for comment. They call it an accident. But i think you and your attorneys believe that negligence caused this accident. Yeah, yeah, its an accident but theres an accounting because someone was negligent. Reporter in a statement to abc news, the park said it was heartbroken over the tragedy and the safety of our staff and our guests is our top priority. The parks verrukt water slide set to be torn down. This is the view from the top of verrukt. Thrillseekers fall 17 stories in send nearly 70 miles an hour. Commercials for the ride even asking are you insane . When the ride first opened three years ago, many were asking a different question. Is it safe . Concerns only heightened after this video from the rides testing phase appeared on the travel channel show extreme water parks. Sandbag dumb hes launching off the slide. The rides opening was repeatedly delayed while designers attempted to work out the kinks, adding in more safety features like netting and safety belts. When it opened it was finally deemed a feat of engineering. I was the first tv journalist to go down. Literally not for the faint of heart. Reporter lifeguards, safety checks, and on this day at least, a park employee at the top of the ride reading a twopage liability agreement. Theres a risk inherent to the activity reporter my first trip down was a vertigoinducing plummet, but overall fun. A complety than the tragedy that unfolded when caleb schwab lost his life. But its easy to see how in a fastpaced ride like this, things can go wrong in an instant. This man was in an austin, texas, slide when he ka reared off the edge, falling down a rocky cliff. He suffered a broken arm and fractured ribs but survived. In this video a man desperately holds on to another rider. After falling off of the raft before eventually being plucked back to safety. Ive got three kids that tale from the ferris wheel. Reporter last august three girls were injured when they fell off the ferris wheel in green county fair, tennessee. Last april in texas a teen died at a church carnival. She was hurled from her seat on a small spinning ride like this one. There nor federal regulations governing amusement parks and the enforcement of state laws is patchwork. The schwabs and their lawyers are trying to change that. But sustaining themselves on faith and friends. Reporter at calebs funeral his Baseball Team huddling with scott. And it was scotts friends who a few months after that funeral took him on a retreat and forced him to spend time grappling with his grief. After caleb was killed, you penned a letter to him. They gave me a notebook, pen. Said, hang out by the river and write a letter to your son, then you need to write the response. So my heart had to say what i never really got the chance to say. It was hard. But it was a release. Reporter calebs brothers keep going by keeping their brother in their minds. Watching those videos. Some of them howto movies he shot himself. So in order to push that button in, we need to take this thing out. And thats kind of the key hole. Reporter and that one of him cradling his little brother. At that now. Then theres other times you cant sleep, you want to look at it. What do you miss most about caleb . Giving him hugs. Hugs. Hearing about his day. My morning hug. Watching him play soccer. Why was it important for you to do this interview . We have a box of greeting cards from around the world. We just want people to know were thankful. Yeah, were still hurting, but were going to be okay. Reporter for nightline im matt gutman in kansas city. Up next, just how did metallica get hooked up with lady gaga for the grammys . Were behind the scenes with the band. Coming back a symptoms kept on my longterm control medicine. I talked to my doctor and found a missing piece in my asthma treatment with breo. Oncedaily breo prevents asthma symptoms. Breo is for adults medicine, like an inhaled corticosteroid. Breo wont replace a rescue inhaler for sudden breathing problems. Breo is specifically designed to open up airways to improve breathing for a full 24 hours. Breo contains a type of medicine that increases the risk of death from asthma problems and may increase the risk of hospitalization in children and adolescents. Breo is not for people whose asthma is well controlled on a longterm asthma control medicine, like an inhaled corticosteroid. Once your asthma is well controlled, your doctor will decide if you can stop breo and prescribe a different asthma control medicine, like an inhaled corticosteroid. Do not take breo more than prescribed. See your doctor if your asthma does not improve or gets worse. Ask your doctor if 24hour breo could be a missing piece for you. Learn more about better breathing at mybreo. Com. Lease a 2017 lincoln mkx for 369 a month. Only at your lincoln dealer. You knmegared omega3s. But did you know your eyes, your brain, and your joints really love them too . Introducing megared advanced 4in1. Just one softgel delivers mega support. Bounty is more absorbent,mom per roll so the roll can last 50 longer than the leading ordinary brand. So you get more life per roll. Bounty, the quicker picker upper so if youve had the privilege of hearing their dead growls in concert, you might be surprised to learn the members of metal car levelheaded family men offstage. Theyve dominated the heavy melt scene over three decades. One of their keys to longevity, they say, is finding work life balance. Downright zen heavy metal. Heres abcs nick watt. Reporter they even shared a mike. After a tech mishap, gaga and metallica rocking the grammys. How did this happen . Gaga has been a sort of selfprofessed metalhead, lifelong metallica fan. We were at dinner six weeks and i said, were doing the grammys, would you like to join . She said yes. It took about 12 seconds. Reporter we were granted exclusive access to a preshow practice in l. A. Friday night. You guys and gaga. Didnt immediately strike me as a natural marriage. By the time she spent, what, like 30, 45 minutes with us, she totally got into the song, worked out vocal arrangement with james, got the feel of the song. It was pretty seamless. My poker face reporter gaga im familiar with, we know poker face among others, a worldwide number one. She played the super bowl halftime show. But these guys . Yeah, ive heard nothing else matters. And nothing else matters never cared what they do im going to come clean. Im more of a Fleetwood Mac kind of guy. I finally understood what your kind of music is about because you can feel it. And without a doubt. It was kind of eyeopening for me. You kind of enjoyed it. I did enjoy it. See, thats the thing. Our message comes by or comes through most accurately, most precisely, when you see us in a live situation. Reporter we all know who metallica are. I mean, you can buy a tshirt at h and m. As for sand man possibly the biggest metallica number. Now i need to know more. I started this band when i was 17. James and i have been together for 35 years. Its the longest relationship ive had with anybody, basically, other than my father. Reporter james hatchfield leads 100 millionplus album sales later, after massive tours on every continent, eight grammys, theyre still here, bigger than ever. Today they announced a north american stadium tour. Now we sit here in our early 50s and go, wow. This is really cool. They keep coming. Reporter in just a few months theyve sold nearly 1 million copies of hardwired to selfdestruct and over 36 years have, well, not selfdestructed. You guys are still playing the grammys. You guys are still selling out stadiums. Youre still number one. Its very honest, what we do. We strap on our instruments, the four of us, what you see is what you get. Reporter this all might never have happened. He came to the u. S. In 1979 from his native denmark to become a tennis player. The black sheep of the tennis side of the family because my father was a professional tennis player. Passion, my hobby, waiting in the wings to take over, and it did. Reporter James Hatfield answered a want ad for other metal musicians to jam with. When james and i started, i was my mom. I never said that before. Thats an exclusive on nightline. You never want to play stiff. Sometimes we look stiff. I love the facial expressions, nice. So you look like youre pissed off, you look stiff. But actually, youre just bringing more impact to the strings. Thats the way i look at it. Reporter bassist rob trujillo has become famous for his crab pose on stage. Im a 43yearold man in tight jeans, im not sure this is going to happen. You always got to make sure your pants are up. Pull your pants up. Then you kind h i cant. Reporter its really about more than just the music. I love playing drums. But i love playing drums in a collective. Drummings the gateway to the adventure. Im not one of these guys that sits around, plays drums for eight hours, always has to tap on something. Reporter 2004, fly on the wall documentary some kind of monster showed a band with some issues. I was straight up with you, i told you, [ bleep ]. What have you been doing . A bunch of guys who have never really had an indepth conversation about how theyre feeling, whats going on, what they think of everything around them over 25 years. All of a sudden it happens. All hell breaks loose. Reporter these days they slow down to smell the coffee. We dont tour for more than two weeks. We have a very strict twoweek care of our families, wives, domestic responsibilities. Then we get a chance to run away with a rock n roll band. Reporter coming to a stadium near you again this summer. Its pretty crazy that people still, 35, 36 years into a career, come, still care, still are passionate, and that theres still a turnover for newer, younger fans. Why do you think people still care and support you . Hard to answer that without i sometimes get a little uncomfortable, sort of hand on heart. Were somewhat good at what we do. Reporter near doesn reporter niche doesnt describe duetting with gaga at the grammys, but hey. Nick watt for nightline in los angeles. Up next, send my love singer adele requesting a doover at the grammys. Whyhe show and try it again. Whether youre after supreme performance. Advanced intelligence. Or breathtaking style. Theres a cclass just for you. 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In our sports cars, you feel every podium weve ever climbed. And now, theyve come together to create something youve never felt before. Introducing the glc coupe. Part suv. Part sports car. All mercedesbenz. Finally, as adele might say, if at first you dont succeed, try, try again. Hello adele opened the gram hes with her signature greeting singing hello. From there on it was her night. But it was the british songstress tribute to the late George Michael that stole the show. As she began a gripping performance of michaels fast love, adele paused and dropped an fbomb. I know its [ bleep ], im sorry, i cant mess this up. This isnt the first time a highprofile artist has had to stop amidst a highstakes performance. Patty smith taking a pau at the nobel prize ceremony in stockholm this past december. I apologize. Sorry im so nervous. Mariah careys new years rocking eve disaster which certainly didnt end as well. Yesterdays hiccup didnt stop the superstars momentum. Capping off the evening by by accepting her fifth and final grammy of the night for album of the year. As you can see, it took an army to make me strong and willing again. And to do it. And i thank you all from the bottom of my heart. But her acceptance speech was flawless. Thanks for watching abc news, and as always, were online at abcnews. Com and our Nightline Facebook page. Good night, america. You know, some people say it takes money to make money. But around here, it just takes guts, brains, and nerves of steel. Does one of our players today have the right stuff . Were about to find out. Lets play who wants to be a millionaire. [dramatic music] welcome to who wants to be a millionaire. You guys ready to go today . All right. From playing pinball to running marathons, our first contestant lives and breathes competition. Shes without a doubt ready to compete against our 14 questions. From chicago, illinois, please welcome liz greenwood. Hey, liz. Hi. Its good to meet you. Come on over. Welcome to millionaire. Thank you. Um, pinball . Yes. Thats a throwback. [laughing] its big in chicago. Im on an intramural pinball team called the pin pals. Wait, stop. Theres such a thing as an intramural pinball. League . Yes. And youre on awhats the whats the size of this team . Uh, its about 8 8 to 10 people. Theres 8 or 10, and yall are called the pin pals . Yep. Thatsi did not know that pinball was still a thing. Oh, yeah. Thats amazing. Mmhmm. I dont even know what questions to ask that would be even remotely. Hows the tilt thing going . [laughing