welcome to a special edition of "world news tonight." the high stakes showdown right here in new hampshire about to begin. the republicans prepping for the spotlight. their last chance to plead their case. we have the all-access pass, just moments away. the candidates stepping up their game. >> i almost want to just go in and pray. >> and stepping up the attacks. >> he's willing to break his word to the voters. >> just three days until new the results could send some packing. the urgent new warning about one of the biggest scams in america. fake phone calls demanding back taxes, threatening arrest. why you're more vulnerable now than ever. and tonight, the health alert for women. do not drink alcohol.

and the other big showdown. super bowl 50. the game plan, the security preps, and who's the new name added to the halftime show? manchester. thank you for joining us on one of the most important nights of the presidential race so far. you can see this crowd right here gathering behind me. tonight's republican debate could be a complete game-changer. the debate field now whittled down to seven candidates. donald trump, back in the mix this time, after skipping that iowa debate. the latest poll numbers just now coming in, showing he is still the clear front-runner. marco rubio and ted cruz right there, tied for second place. and this, take a look, a live look at the debate hall right now. the energy building all across this state, but especially right here where the candidates will soon face each other and the

abc's tom llamas starts us off >> reporter: tonight, the stage is set. and candidates like senators ted cruz and marco rubio getting a change the direction of this race. rubio expected to take on the most fire tonight. his poll numbers rising, and so are the attacks against him. like from cruz, who is reminding voters who really won in iowa. >> what did you think about the really impressive third place finish of marco rubio? that's an odd collection of words, impressive, third place finish. >> reporter: rubio calling out cruz for his campaign's efforts on caucus day to suggest dr. ben carson was dropping out of the race, which was not true. >> by the way, if you get a call on tuesday night saying that i dropped out, it isn't true, it's a lie. keep voting. >> reporter: and donald trump, leading in the polls here, but the race is tightening, starting the fight early, tweeting today, "wow, jeb bush, whose campaign is a total disaster, had to bring in mommy to take a slap at

>> vote for jeb. >> oh, yeah. >> reporter: but that tweet's not stopping 90-year-old barbara bush. >> he doesn't give many answers to how he would solve problems. he sort of makes faces and says insulting things. >> reporter: jeb, bringing in his famous mother to help lift his campaign off life support. today, an encouraging sign. a crowd of more than 600. bush says he's his own man, but won't run from his famous last name. >> people are just going to have to get over it, all right? it's -- i am who i am, you know? it's -- it's -- i'm in the establishment. >> reporter: bush, part of the pool of governors that includes chris christie and john kasich, hampshire. today, kasich getting a boost from another notable republican governor, arnold schwarzenegger, who compared him to that bullet-proof robot that made him famous. >> it absolutely would not stop.

you are the terminator. >> and tom, right here with me inside the debate hall. tom, you're hearing one of the biggest fights tonight might actually be a rematch? >> reporter: that's right, cecilia. get ready for jeb bush versus marco rubio part two. all week, bush has been hammering rubio, saying he has zero accomplishments. a top bush aide even calling rubio a no-show lobbiest. the rubio campaign says that bush is desperate, and they're going to be ready for anything tonight. i want to point out, cecilia, both of those men will be standing right next to each other on that stage. >> anything could happen. tom llamas covering the republican race every step of the way. tom, thank you. one reason tonight's debate could shape the direction of this race, nearly half of all republican voters in new hampshire have yet to make up their minds. so, what are they waiting to hear? here's abc's jon karl. >> reporter: as the candidates make the final push in new hampshire -- >> show time is over. it's game time. >> reporter: -- the republican

donald trump still leads all the polls, but marco rubio is rising. and cruz, kasich and bush are not far behind. it's just three days to go before the primary, and at the chez vachon diner in manchester, we found folks ready to pick a president. well, almost. clearly you've made up your mind now, right? >> well, we haven't. >> reporter: you haven't made up your mind? >> we haven't made up our mind. >> reporter: he's not alone. amazingly, more than 40% of likely republican voters in new hampshire say they still haven't made up their minds. he's narrowed it down to trump, rubio or cruz. >> i think we're stuck on -- will we actually have the nerve to vote for trump? i mean, that's really where we're stuck. >> reporter: so, when you go in there, are you able to pull the lever for donald trump, is the question. >> yeah, that's it. i mean, a year ago, i couldn't imagine voting for trump. >> reporter: but there are two groups who seem totally decided. front-runner -- >> reporter: no matter what? >> no matter what. i heard him.

no changing my mind. >> reporter: and those who don't. >> i definitely know i would not vote for trump. that's all i really know. >> reporter: but new hampshire voters have a long history of making up their minds late and surprising everybody. after barack obama won the iowa caucuses eight years ago, he was way ahead in the polls here in new hampshire, but ended up losing to hillary clinton. this time, it's the republicans who seem most undecided. so, when will you make up your mind up, finally, totally make your mind up? >> i'd say really after this last debate. >> and so many people still waiting to make up their mind. jon joins me now inside the debate hall, too. jon, donald trump not at that last debate. we know he will be here tonight. what are you hearing from the campaigns about his strategy? >> reporter: well, trump's xaun manager says if he is attacked tonight, he will respond in kind, times ten. but we really don't know which donald trump will show up tonight.

we've seen him go nuclear on his opponents, accused ted cruz of cheating in iowa. but we've seen him show incredible restraint. cecilia, we have never seen him debate after a loss. we just don't know which one will show up. >> and we will see it soon. jon, thank you. abc political analyst matt could is dowd is here with me. who has the most to win here tonight who has the most to lose? >> well, it's pivotal for all seven up there tonight, but i would like to focus on three folks. john kasich has put all his chips on the table here. he's done 100 town halls and he has to figure out a way tonight to jump himself to second or third. the other person with the most to gain is jeb bush. he's spent more money than any other candidate in this race, and if jeb bush doesn't finish in the top four on tuesday, then his candidacy is on life support. and donald trump has the most to lose. he has been ahead and he is ahead by double-digits. he's led 70 straight polls since july here. and he cannot afford another second place finish, otherwise his campaign is seriously

>> the whole team here covering it all. matt, you'd be back later. thank you. the countdown is on for the democratic candidates, too. bernie sanders, the favorite son here. hillary clinton, the underdog. she was out going door to door herself today, while he was speaking inside before a packed hall. abc's david wright is on the trail. >> it's a beautiful day in manchester! >> reporter: hillary clinton may be down in the polls here in new hampshire, but don't count her out yet. >> well, i need your help on tuesday, and convince some others to come along. >> reporter: today, she's been out pounding the pavement, knocking on doors, trying to make up ground against bernie sanders. >> i feel like a rock and roll star. >> reporter: sanders has accused favorite democrat. not progressive enough. >> i have spent my entire adult life trying to knock down barriers. >> reporter: today, madeleine albright joined clinton, appealing to women, in particular.

who don't help each other. >> reporter: but some of the people attending clinton's own event agree with sanders. >> probably for bernie sanders. >> i'm actually a bernie supporter. >> reporter: you're a bernie supporter? but you're here at a hillary >> i am. >> reporter: do you feel like you are behind enemy lines? >> kind of. >> reporter: today at a town hall at new england college, the first questioner made a freudian clip. >> secretary sanders -- >> reporter: calling her by her opponent's name. clun clinton took it in stride. >> there are a lot of young people that support my opponent. but i want you to know, even if you don't support me, i support you. >> reporter: the sanders surge here is clearly a nuisance for clinton. but it will be interesting to see tonight on that debate stage how seriously the republicans take him. it's a pretty safe bet they'll mention her name more than his. cecilia? >> i think that's safe to say. david wright, thank you. and, of course, the debate, you do not want to miss it. just moments away.

right here. but we do now move on to other news. to that deadly crane accident in new york. the move that went out of control, and the crane's sudden collapse, caught on camera. the cab of that crane landing upside down, its arm smashing onto cars below. one man killed, three others injured. abc's phillip mena with the latest on the investigation tonight. >> reporter: tonight, a massive job. moving this collapsed crane, all 565 feet of it. crews forced to use blow torches to tear it apart, after it came crashing down friday morning in new york city. killing one and injuring three, crushing cars and sending this counterweight into a building. you can see all that debris still on the road there. some of it came from the top of that damaged building, where part of the crane still lies. the unanswered question tonight, what triggered the collapse? officials looking closely at the wind and snow conditions. how long do you think before we can figure out exactly what

>> you know, i think you're going to have to give us a couple of weeks at least while we do some engineering calculations, go through the metal and how it failed. >> reporter: officials say the operator tested negative for drugs and alcohol, and has been cooperating with the investigation. this crane is so big that workers are having to cut it into 35 pieces just to clear it from the street. cecilia? >> phillip, thank you. we turn now to a health alert. the cdc apologizing tonight after a controversial recommendation to women. it says women should refrain from drinking alcohol, saying the risk to babies is too high. the reaction, fierce. many women saying that advice goes way too far. here's abc's gloria riviera. >> reporter: women across the country, sounding off over the cdc's new alcohol and pregnancy. >> it just makes no sense to me. >> are you serious? is this really what you feel comfortable telling your wife, your sister, your daughter?

support the cdc's long-standing warning about the dangers of drinking while pregnant, the new guidelines hit a nerve, because they go further, telling health professionals to advise a woman to stop drinking if she is trying to get pregnant or not using birth control with sex. outrage exploding on social media. calling the advice patronizing and reactionary and sexist. the women we spoke to, telling us they can be trusted to make smart, safe choices. >> i really do feel they are overstepping their boundary in terms of what a woman can do with their own body. >> this is, perhaps, the right intention, with a very wrong execution. >> reporter: the cdc points out, half of all pregnancies in the u.s. are unplanned. many women don't know they are pregnant for several weeks. possibly unintentionally putting their child at risk. today, the cdc telling abc news, "we were sorry some people took offense at our communications." the cdc is standing by its

intended to clearly explain the risk drinking may have on an unborn child. cecilia? >> okay, gloria, thank you. and the debate stage set to take place right here in this hall, it's not the only showdown this weekend. the super bowl now less than 24 hours away. more than 100 million people will be watching. the stage is set in san francisco. and abc's ryan smith has the big ticket. >> reporter: super bowl frenzy in full effect. >> broncos! >> carolina! >> reporter: just 24 hours before super bowl 50, and fans are fired up. a clash of football's titans. all-time great peyton manning and the dazzling, dynamic cam newton. >> you don't go 17-1 as a starting quarterback without being awesome. >> peyton manning will always be an all-time great. >> reporter: and to set the bar even higher, bruno mars confirming he will be apart of the highly anticipated super bowl halftime show.

security, not taking a backseat. we're standing here in one of the security operations centers for the super bowl. there are multiple ones so they can back each other up. and what are they looking for? well, they are looking on the streets, the stadium itself, even the air space, to make sure that super bowl sunday is a safe one. safety is paramount. for players and fans alike, hoping the 50th super bowl is one for the ages. so, who will win the super bowl here at levi's stadium? las vegas odds makers have the carolina panthers at 5.5-point favorites. and while most people we spoke to here have the broncos as the sentimental choice, they're picking the panthers to win it all. cecilia? >> going to be a good game. ryan, thank you. and still ahead on this special edition of "world news tonight," the threatening phone calls to watch out for. >> within the next hour, they will be at your doorstep to handcuff you and put you behind bars. >> a tax scam warning. why you may soon be more at risk

and later, the president of a fraternity at an ivy league university under arrest. the allegations rocking that km pus. what he is accused of doing that

my man, lemme guess toenail fungus!? whaaat?!? fight it! with jublia. jublia is a ...used to treat toenail fungus. use jublia as instructed by your doctor. jublia is workin' it! most common side effects include... ...ingrown toenail, application site redness,... ...itching, swelling, burning... ...or stinging, blisters, and pain. oh!! fight it! with jublia! now that's a red carpet moment! ask your doctor if jublia is right for you. visit our website for savings on larger size. there has to be a way. carry the centimeter, divide by 3.14 something something something... [ beeping, whirring ] great caesar salad! and now the name your price tool shows people policy options to help fit their budget. is that a true story? yeah! people really do save an average of over $500 when they switch. i mean about you inventing it. i invented the story, and isn't that what really matters? so...

whether we like it or not, tax season is here. tonight, a warning. scammers working the phones to get their hands on your money. and those suspicious calls and threats cost americans millions. here's abc's ron claiborne. >> within the next hour, they will be at your doorstep to handcuff you and put you behind bars. >> reporter: the government is warning americans to be on high alert for a growing phone scam that is bilking americans out of millions of dollars. this chicago area woman got a call like that in december, from someone claiming to be from the irs, demanding she pay thousands of dollars in back taxes. >> and if we don't, there's a

>> reporter: scared, she wired $10,000 to an account in seattle. it was all a scam. the irs says, since october 2013, 5,000 victims, losing more than $26 million, to people pretending to be irs officials. so, how do you protect yourself? for years, the government has had this simple message. >> they often use a fake telephone number with a u.s. area code. they demand immediate payment. they may threaten arrest or deportation. >> reporter: starting next month, a new law requires the irs to hire collection agencies to help collect taxes. and those agencies may call taxpayers. >> in the future, when collectors are actually calling on behalf of the irs, people will be more likely to fall for that scam. >> reporter: paying taxes they don't owe. ron claiborne, abc news, new york. when we come back, held hostage during that bonnie and clyde crime spree. how the dangerous couple held

what that family is saying tonight. and, fading out? why some of our favorite candies may soon look a little bit different. t type 2 diabetes doesn't care who you are. man woman or where you're from. city country we're just everyday people fighting high blood sugar. i am everyday people. farxiga may help in that fight every day. along with diet and exercise, nfarxiga helps lower blood sugar in adults with type 2 diabetes. r r one pill a day helps lower your a1c. r r and, although it's not a weight-loss or blood-pressure drug, r r farxiga may help you lose weight and may even p p lower blood pressure when used with certain diabetes medicines. p p do not take if allergic to farxiga or its ingredients. p p symptoms of a serious allergic reaction include rash, swelling, r or difficulty breathing or swallowing. r if you have any of these symptoms stop taking farxiga r r and seek medical help right away. ndo not take farxiga if you have severe kidney problems, t are on dialysis,

p p tell your doctor right away if you have blood p p or red color in your urine or pain while you urinate. p p farxiga can cause serious side effects, including dehydration, r genital yeast infections in women and men, t low blood sugar, kidney problems, and increased bad cholesterol. p p common side effects include urinary tract infections, changes in urination, and runny nose. farxiga. r yeah. yeah. ask your doctor if farxiga is right for you and visit farxiga.com to learn how you can get it for free. i've been on yea me too. excuse me...coming through! with dr. scholls they're proven which helps you feel more energized ...all day long. i want what he has. i accept i do a shorter p i even accept i have a higher

tnot caused by a heart valve problem. but i won't play anything less than my best. so if there's something better than warfarin, i'm going for it. eliquis. reliquis reduced the risk of stroke better than warfarin, plus it had significantly less major bleeding than warfarin... eliquis had both... that's what i wanted to hear. ndon't stop taking eliquis unless your doctor tells you to, p as stopping increases your risk of having a stroke. neliquis can cause serious and in rare cases fatal bleeding. p r while taking eliquis, ...and it may take longer than usual for any bleeding to stop. nseek immediate medical care for sudden signs of bleeding, like unusual bruising. p eliquis may increase your bleeding risk p tell your doctor about all planned medical r i accept i don't play ...quite like i used to. but i'm still bringing my best. and going for eliquis.

plus less major bleeding. ask your doctor... ...if switching... ...to eliquis is right for you. and to the index now. tonight, an ivy league university rocked by rape allegations. the president of cornell's psi upsilon fraternity is facing attempted rape charges. 21-year-old wolfgang ballinger was arrested after turning himself in. the fraternity now placed on suspension. and to that bonnie and clyde crime spree. the frightening moment when this woman's husband spotted the dangerous couple right in their back p

>> he saw a man standing there with a gun pointed at him, saying, open your door. and -- what do you do? >> the florida family held hostage for three hours. suspect blake fitzgerald was later killed in a police shootout. brittany harper is still in custody. and a candy giant making some healthy changes. m&ms and skittles are getting a makeover. candymaker mars is vowing to remove all artificial coloring from its products. the plan is to come up with healthier ingredients to create those vibrant colors over the next three years. and stul a astill. and still ahead on "world news tonight," it is almost time here. we are just waiting for the candidates to take the stage, all backstage? come back. me to reach my goals. my doctor told me i may reach my blood sugar and a1c goals

with once-weekly trulicity. trulicity is not insulin. it helps activate my body to do what it' s supposed to do release its own insulin. trulicity responds when my blood sugar rises. i take it once a week, and it works 24/7. it comes in an easy-to-use pen and i may even lose a little weight. trulicity is a once-weekly injectable prescription medicine to improve blood sugar in adults with type 2 diabetes. it should be used along with diet and exercise. trulicity is not recommended as the first medicine to treat diabetes and should not be used by people with severe stomach or intestinal problems, or people with type i diabetes or diabetic ketoacidosis. trulicity is not insulin and has not been studied with long-acting insulin. do not take trulicity if you or anyone in your family has had medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2 or if you are allergic to trulicity or its ingredients. stop using trulicity and call your doctor right away if you have symptoms of an allergic reaction, such as itching, rash, or difficulty breathing;

such as severe stomach pain that will not go away and may move to your back, with or without vomiting; or if you have symptoms of thyroid cancer, or swelling in your neck, or shortness of breath. medicines like trulicity may cause stomach problems, which could be severe. your medical conditions and any medicines you take. sulfonylurea or insulin for low blood sugar. common side effects include nausea, diarrhea, vomiting, decreased appetite, and indigestion. some side effects can lead to dehydration, which may cause kidney failure. with trulicity, i click to activate what' s within me. if you want help improving your a1c and blood sugar numbers with a non-insulin option, ask your doctor about once-weekly trulicity. your within. equals great rates. s a fact. equals free tech support. so great to see you! none of this works.

this is sheldon whose long day setting up the news starts with minor arthritis pain and a choice. take tylenol or take aleve, the #1 recommended pain reliever by orthopedic doctors. just two aleve can keep pain away all day. back to the news. hi hey thank you, i feel good. it all starts with eating right. that's why i eat amaz!n prunes now. they're delicious and help keep my body in balance. i love these.

it's a packed court right here behind me. it is almost time. we went behind the scenes today, right behind this stage. and it turns out, the tricky part is keeping all these candidates from passing each other in the hallway before they even step into this spotlight. the stage is set, the finishing touches complete. but you already knew all that. here's what you don't know. underneath those podiums -- we are in the athletic center of st. anselm. the candidates won't cross paths until they're ready to take the stage. take a look at this. this is one of the candidates' dressing rooms. you can see whose it is right here. just to burn off a little bit of steam before a debate, i don't know, maybe he wants to ride an exercise bike? long hallways. arrows telling the candidates where to go. this is a racketball court. candidates will be in there -- no, no candidates will be in

the long walk to that stage. >> guys ready? >> and then, all those rivals standing there, waiting side by side until their name is called. >> donald trump. >> it's rehearsal time today. the fill-ins, students playing the role of a lifetime. as you can see, this is not the real jeb bush. i mean -- maybe. you have a good one-liner? >> i got the kneeldown, though. >> let's see. >> i got it down. i'm always staring at marco when he says something, too. >> you totally have it down. that's really good. let's see, best chris christie face? the whole gang is here. oh, hi david and martha. ready to go. and it all starts -- >> applause, applause. still applause. and -- go. >> the whole gang is, indeed, here. it does start right here in just a matter of moments. you can hear this hall buzzing behind me. the fireworks about to begin. i'm cecilia vega in new hampshire. thank you so much for watching. and we will see you right back