>> don't tell me he doesn't know who the ku klux klan is. >> now, trump fighting back. hillary clinton in a landslide win over bernie sanders in south carolina. >> i believe that america is great, right now. >> sanders admitting he was decimated. but vowing, he's not out. rookie officer killed. the female police officer gunned down on her first day on the job. the call for help that turned deadly. and what we're learning tonight about the alleged gunman. trapped in midair. the nose dive crash that ended like this. the 87-year-old pilot trapped for hours. how rescuers finally got him out. countdown to the oscars. on the red carpet, and behind the scenes. the controversy. the chris rock factor. and a beefed up oscar. the award's new look. and good evening. thank you for joining us on this sunday. i'm tom llamas.

oscars tonight, but also super tuesday, just two days away. the high stakes showdown. republican front-runner donald trump, under fire tonight. the race issue exploding. critics demanding he denounce the ku klux klan. marco rubio on a relentless attack, calling trump a conman. as senator ted cruz goes even further, suggesting trump won't release his tax returns because he has possible mob ties. abc's mary bruce starts us off tonight. >> donald trump! >> reporter: tonight, donald trump on the defensive, forced to explain this answer when asked if he condemns the ku klux klan and its former grand wizard, david duke's call to vote for trump. >> i'm just talking about david duke and the ku klux klan here. but -- >> i don't know anything. hon honestly, i don't know david duke. i don't believe i've ever met him. and i just don't know anything about him. >> reporter: the backlash was swift. his rivals pouncing. >> we cannot be a party that nominates someone who refuses to condemn the ku klux klan.

that. >> reporter: ted cruz tweeting, "really sad. donald trump, you're better than this. we should all agree, racism is wrong. kkk is abhorrent." trump fired back, noting this previous response. >> i didn't even know he endorsed me, david duke endorsed me? okay, all right. i disavow, okay? >> reporter: trump is poised to win big on super tuesday. which includes six southern states. trump boosted by his huge endorsement from former rival chris christie. the new jersey governor was challenged today on his change of heart about the front-runner. >> are you saying now that you endorse ban of having noncitizen muslims -- >> no, that's not what i'm saying. i'm saying that's only one piece of an overall approach -- >> you disagree with that? >> i said that very plainly. >> reporter: with just two days until the next contest, the rival campaigns have turned into attack machines. hammering trump for not releasing his tax returns, speculating about what he's hiding. >> there have been multiple media reports about donald's business dealings with the mob, with the mafia.

to release the tax returns, just not now, because of an ongoing irs audit. and tom, here tonight, marco rubio hoping to get some more momentum heading into tuesday, but he has a long way to go. and making it harder, donald trump just nabbed another big endorsement. he now has the backing of alabama senator jeff sessions. tom? >> a big endorsement for trump tonight. all right, mary, thank you. now, to the democrats. hillary clinton, riding that wave of momentum into super tuesday. clinton winning south carolina by almost 50 points. receiving huge support from a record turnout among black voters. bernie sanders vowing not to give up the fight, promising to challenge clinton until the very end. abc's david wright with the clinton campaign in arkansas tonight. >> reporter: in nashville, today, a scene straight out of abc's "scandal." the actor who plays the president made a show of telling the candidate who hopes to be president about donald trump's

>> you heard about his latest. >> what has he done now. >> he wouldn't disavow the kkk and david duke because he didn't know who david duke was. >> oh, that's pathetic. >> reporter: clinton's huge victory in south carolina has put a new spring in her step, heading into super tuesday. she has more delegates and more momentum than bernie sanders, as sanders freely admitted to george. >> we got decimated, george. we got decimated. >> reporter: clinton's mood, buoyant. >> i'm actually kind of looking forward, if i'm fortunate enough to with be the nominee, debating any one of them. >> reporter: she's also pointedly making nice. creating a contrast with some of the republican rhetoric. >> i think we need more love and kindness. >> reporter: now, most of the super tuesday states are right here in the south, and that should play to hillary clinton's strengths. but it plays into the expectations game, so, if bernie sanders is able to score a few big unexpected wins, well, the

tom? >> and david, on that point, let's get right to abc's chief white house correspondent jonathan karl. jon, what's senator sanders' path to stop clinton at this point? >> reporter: well, it's a narrow path. he has to do much better than expected on super tuesday. he has to show that he can win in the south, or come really close. and then, he has his eyes on the prize of california. the biggest delegate stake of all. he thinks he can win there. but you know, that's not until june. and if he doesn't do better before then, he'll be out of it. >> we're less than 48 hours from the voting on super tuesday. do you think this kkk controversy hurts donald trump? >> reporter: the honest answer is, we don't know. on one hand, he's retweeted white supremacists in the past and not faced much of a backlash, but i think this could be different. look at the way his rivals immediately pounced on it. and look at the way he felt the need almost immediately to come out and clarify and say, yes, i disavow david duke. republican primary voters will tolerate a lot, but i don't think they will tolerate outright racism. >> jon, thank you.

special editions of "good morning america" and "world news tonight", george stephanopoulos and the entire powerhouse political team on the air, beginning at 10:00 p.m. eastern, tuesday night. and we do move on now to virginia, the deadly police shooting making national headlines tonight. a rookie officer shot and killed her first day on the job. two other officers wounded. her police cruiser today, you see it there, turned into a memorial with black bunting, a wreath placed on the hood. the alleged gunman, an army staff sergeant, assigned to the pentagon. abc's gloria riviera on the investigation tonight. >> reporter: tonight, a police department in the tight knit community it serves devastated by a shocking loss. prince william county, virginia, officer ashley guindon killed in the line of duty on her first day on the job. >> when news came that she passed, it was -- it hit us. we weren't expecting it at all.

officer responding to a 911 call, reporting domestic abuse. >> i just want to be clear. do we have officers involved in a shooting? >> we have three officers that have been shot. >> reporter: it was here in this quiet upscale neighborhood that rookie cop ashley guindon and two others approached that front door. police say almost immediately the suspect confronted them, opening fire, and they all went down. >> i saw the officer laying right there, holding his leg, i figure he got shot. >> reporter: neighbor zach harris saying he heard three gunshots. police identifying the as army staff sergeant ronald hamilton, assigned to the pentagon. investigators saying hamilton's wife was found dead inside the home. his 11-year-old son also home but not hurt. the two other officers are expected to recover. now, officer guindon's squad car, draped in black to honor the rookie lost too soon. ronald hamilton is expected to appear in court tomorrow. he is facing two murder charges, murder in the first and capital

the death penalty if convicted. tom? >> incredibly sad story. okay, gloria, thank you. overseas tonight, the fragile cease-fire in syria. reports of russian air strikes hitting targets in the cities of aleppo and raqqah. syrian families caught in the middle, hoping the truce holds long enough for much-needed humanitarian supplies to arrive. abc's alex marquardt in the region for us tonight. >> reporter: air strikes today in northern syria. just one of a growing number of incidents threatening this fragile truce. both sides accusing the other of violating the cease-fire. but tonight, it has largely held for a second day. the fight continues against isis and al qaeda, but in much of syria, there's a calm that hasn't been felt for years. still at risk, the almost half a million people living under brutal sieges. in one town, local doctors say dozens have died from starvation. we tried to visit today, with government permission, but were

dangerous. but the united nations is now trying to capitalize on the quiet, to ramp up deliveries of aid across the country. the u.n. says if this truce holds, they can do more, better and faster. that will be tested tomorrow morning, when the first aid convoy is scheduled to go out since this temporary cease-fire started. tom? >> alex marquardt for us tonight. alex, thank you. back here at home, a plane crash in pennsylvania. the 87-year-old pilot plunging into the trees, reporting engine trouble just after takeoff, suddenly trapped in midair. you can see it there. abc's phillip mena on the rescue effort to get him back on the ground. >> reporter: dangling from the branches, this small plane left hanging from a tree, nose down, after a frightening crash. the only person on the plane, the pilot. 87-year-old herbert bartell, waiting hours to be saved. while rescue crewed figured out how to get him down. police say bartell had just taken off when he ran into

>> the engine started to sputter and he lost control. so, he tried to do a u-turn, but he lost control and it went into the trees. >> reporter: stuck up in the tree, bartell managed to call 911, but it took nearly four hours to get him down, because of all the branches in the way. >> he was in very good spirits the whole time there. he was conscious, alert, oriented the whole incident. >> reporter: bartell escaped with only minor injuries. >> think by the end he was a little anxious to get out. >> reporter: phillip mena, abc news, new york. now, to hollywood. the academy awards about to get under way tonight. the star power building on the red carpet. the biggest celebs in the business about to arrive. everyone picking their favorites to win. abc's amy robach at the dolby theatre. >> reporter: hello from hollywood, tom. the excitement is building as the stars begin to make their way down the red carpet. it does not get more glamorous than this. this is a night when hollywood truly shines and as far as the awards go, well, hollywood loves an underdog, so, don't count anyone out.

this year, leonardo dicaprio may not walk away empty handed. that bear attack in "the revenant" may give leo the lock for the best actor award. newcomer brie larson is leading the best actress pack. sylvester stallone may land a knockout in the best supporting actor race. the alicia vikander, best supporting actress. and, so, it is still anyone's guess. only two people from the account accounting firm pricewaterhousecoopers know the results of tonight. and, so, right now, it is certainly hollywood's best kept secret and we'll all just have to wait. tom? >> we'll be tuning in. all right, amy, thank you. and it's not just the oscar nominees getting all the attention this year. a lot of attention over who was left out. the controversy over lack of diversity sure to be a topic on stage tonight. let's get right to robin

>> reporter: hello there, tom. the oscars have finally arrived, and we are right in the thick of it here at the dolby theatre. the movers and shakers of the film industry, and, of course, the stars are starting to make their way in, and we congratulate all of the nominees. this year, so much of the attention on those who were not nominated. the lack of diversity among the nominees, setting off, as you know, a firestorm. host chris rock making it clear, he will not shy away from the controversy, tweeting "see you sunday. #blackout #oscars." and tonight, so many are wondering just how far chris rock will go when he confronts the issue. we're going to have it all and we're going to have interviews with some of this year's nominees, of course. all in our oscar preshow countdown to the oscars. that's coming up right after "world news tonight." tom? >> it is shaping up to be an incredible night. robin robin, thank you. still ahead tonight, danger on the roadways.

keep their eyes on the road. debris flying right at them. how to stay safe. and protests erupting in an american city. the police shooting sparking outrage and the investigation tonight. what if one piece of kale could protect you from diabetes? what if one sit-up could prevent heart disease? one. wishful thinking, right? but there is one step you can take to help prevent another serious disease. pneumococcal pneumonia. if you are 50 or older, one dose of the prevnar 13 vaccine can help protect you from pneumococcal pneumonia, an illness that can cause coughing, chest pain, difficulty breathing, and may even put you in the hospital. even if you have already been vaccinated with another pneumonia vaccine, prevnar 13 may help provide additional protection. prevnar 13 is used in adults 50 and older to help prevent infections from 13 strains of the bacteria that cause pneumococcal pneumonia. you should not receive prevnar 13 if you have had a severe allergic reaction to the vaccine or its ingredients. if you have a weakened immune system,

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windshield. >> reporter: luckily, no one was hurt. but tom catanko, driving on an indiana highway last week, came inches from death. >> it's a little sore. >> reporter: when a five-pound metal spring came off a semi, sailing through his windshield. it happens more than you think. debris triggering roughly 50,000 crashes a year. claiming nearly 450 lives. to prevent accidents like this one, caused by a mattress landing in the road, experts say the best thing you can do is be aware. >> trust your instincts. increase your following distance. make sure that no vehicles are beside you, which gives you ample room in case you have to veer into another lane. >> reporter: and if you don't have that escape route, experts say the best thing to do is s drive through that debris and try not to slam on your brakes. tom? >> all right, linzie, thank you. and when we come back, a

want to miss. what was in this gift-wrapped box that had one little boy jumping for joy? and an arena full of basketball fans on their feet. some of them in tears. and this year's oscar statues. the winners may notice a change. why oscar's looking a bit more buff. stay with us. with my moderate to severe ulcive colitis, the possibility of a flare was almost always on my mind. thinking about what to avoid, where to go... and how to deal with my uc. to me, that was normal. until i talked to my doctor. she told me that humira helps people like me get uc under control and keep it under control when certain medications haven't worked well enough. humira can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers, including lymphoma, have happened; as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. before treatment, get tested for tb.

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overtime when that happened. curry breaking the record for most three-pointers in a season with 288 so far, tying the record for most three-pointers last night in a game, 12. and beating oklahoma city along the way. now, to a little boy showered in gifts by his favorite basketball team. but that's only part of the story. the phoenix suns wanted to cheer up little kaya bella, who had been missing his father, a soldier deployed for a long time. then came this big box. and guess who popped out? >> daddy! >> what a moment. the crowd erupted watching the emotional reunion. no doubt, the best present ever. and now, to the academy awards. and it looks like oscar may have a personal trainer. the actual statue is getting a makeover this year. they've been revamped with more muscles, refined jawline and hairline. the subtle features look more like the original statues did in 1929. they will also be hand cast in bronze, like the originals,

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big moment in anyone's life. like when jennifer connelly con supporting actress in 2002. you don't want to forget anyone. still, nothing sinks the heart of an oscar producer like a litany of thank yous. >> thank you to all of our magnificent cast. >> reporter: there was al pa economy in pachino in 1993. >> if you indulge me for a moment, i had to write this down. >> reporter: not every winner has pacino's star power. so, some get played off. as will farrell and jack black famously sang -- no need to thank your parakeet you're boring look at catherine zeta-jones she's snoring >> reporter: this year's oscar producers, david hill and reginald hudlin, hope they've hit on a plan to perk up 2016's 45-second acceptances.

screen that will name all the names a winner needs to thank, as they explained to abc's lara spencer. with a list. they don't have to find the glasses. >> oh, my god. >> you know, it's like, look. you can thank more people, you can thank the same people. you can -- >> thank your cat. >> make a statement. >> reporter: the hope is for unmistakable moments of emotion and deeply felt appreciation. the kind that have become part of oscar legend. who could forget cuba gooding jr.'s wrapup from the oscars in '93? >> i just want to -- oh, here we go. okay, the studio, i love you, cruise! i love you, brother! i love you, man! >> reporter: and if the orchestra never has to play anyone off the stage, audiences around the globe will all be feeling, well, really grateful. chris connelly, abc news, los angeles. >> and we hope tonight has lots of moments just like that. academy awards. the red carpet starting to fill up. don't miss robin roberts'

and then the 88th academy awards right here on abc. a complete wrapup of the oscars on "gma" tomorrow morning. david muir right back here tomorrow night.

have a gre good evening, everyone. i'm robin roberts. welcome to the biggest night in hollywood! we're live on the most famous red carpet in the world.

here's a view you don't usually get to see. tonight, the biggest stars in the universe are here for the 88th annual academy awards. you can see the photographers are. and so is michael strahan. wonderful. >> it is great to be here. and you look amazing. >> thank you, thank you. we're going to have a great time. because, this is hollywood, super bowl and the excitement starts right now. >> life is full of dreamers. some dream of falling in love. others dream of changing the world. but there's one night we all dream in gold. >> on this one extraordinary night. dreams come true. >> no matter where you're from, your dreams are valid. >> exhilarating. glamorous. breathtaking. wondrous. >> thank you so much! >> wow! >> and right now, with all the world watching, this is where