tonight, on this first day of 2017, an urgent terror manhunt. a gunman opening fire in a popular nightclub packed with new year's revelers. the graphic moments caught on camera. more than three dozen killed in the massacre. now, the security warning for americans. a deadly mid-air collision. the fiery debris crashing down near a busy shopping center. witnesses running for cover. >> donald trump's new promise on russian hackers. the new information he says he'll reveal. and his advice to americans worried about cyber security. a pair of dangerous new year's day stunts. first, hollywood wakes up to a transformed landmark. then, an nfl game disrupted. protesters going to extremes.

mishap. the pop star's disastrous endnote to 2016. >> well, happy new year. we can't hear, but -- >> what she now says caused the meltdown with millions watching. good evening. happy new year. i'm cecilia vega, in for tom. 2017 begins with a deadly terror attack and an all-out manhunt for the killer. video showing the graphic images, the motion a gunman fires as he approaches the upscale club in istanbul, turkey. at least 39 confirmed fatalities, dozens more injured, including

and a warning to americans in istanb istanbul, telling them to shelter indoors. it's a grim new year's day for a country repeatedly targeted by extremi extremism. here's alex marquardt. >> reporter: this was the scene in istanbul's popular upscale reina nightclub at midnight. >> ten, nine, eight -- >> reporter: the partiers dancing, waving sparklers, confetti flying as the new year is rung in. >> three, two, one! >> reporter: but just over an hour later, surveillance video captures this ominous scene just outside the club. bullets ricocheting on the street, people running for cover. from the opposite angle, graphic video of a man dressed in black, pointing his rifle. authorities say the suspect killed a police officer and another person on the street before storming the club. the view from inside shows a gunman dressed in white, wearing a hood. authorities believe the attacker changed clothes.

he stayed inside for seven terrifying minutes, shooting at the crowd that had gathered. an estimated 600 people. "my husband told me to get on the ground, then a man came," this woman says. "on my left, right, everyone was crying. the smell of gunpowder was everywhere." revelers reportedly jumped into the city's bosphorus river, next to the club, desperate to escape. in the chaos, the attacker slips away. and tonight, is still on the run. an eyewitness captured this video of the immediate aftermath. a man's body lying in the street, panicked yelling as ambulances race to the scene. survivors crying, embracing each other. still dressed to celebrate. at least 39 people dead tonight including more than two dozen foreigners, the club popular with tourists. dozens more were injured, including at least one america

today, an anguished son weeping over his father's casket. as authorities scramble to find the person responsible. americans warned by the consulate to shelter in place. the u.s. and turkey calling it a terrorist attack. so far, there has been no claim of responsibility. tonight, turkish police sources tell us they believe the shooter showed signs of being a trained isis fighter. >> alex, thank you. and that manhunt under way right now in a country targeted by several recent terror attacks. nearly 300 killed there in 2016 alone. in june, three suicide bombers stormed the airport with assault rifles. 44 killed, nearly 150 wounded. and two weeks ago, russia's ambassador to turkey was killed. and steven ganyard, w

heard alex's reporting that turkish police believe the most recent attack was carried out by a trained isis fighter. what clues have you seen? >> in this case, it's the target that gives us the indication it may be i.s. the night club, in bali, orlando, paris, the idea that it's a target, a symbol of secular decadence that makes it a target for terrorists. and back here at home, the president-elect and wife melania celebrating at mar-a-largo, before saying he'll reveal new details. mary bruce is at the white house. >> reporter: tonight, donald trump is ringing in the new year with new pushback.

and hacking is a very hard thing to prove. so it could be somebody else. >> reporter: the president-elect at his new year's eve bash in florida, still doubting u.s. intelligence and questioning if russia interfered in the election. >> i want them to be sure. i think it's unfair if they don't know. >> reporter: but 17 u.s. intelligence agencies concluded russia was behind the hacking. now trump suggests there's more to it. >> i also know things that other people don't know, and so they cannot be sure of the situation. >> reporter: trump will be briefed by leaders of the intelligence community next week and is promising more details. >> what do you know that other people don't know? >> you'll find out on tuesday or wednesday. >> reporter: the top democrat on the house intelligence committee tells our jonathan karl the evidence is ironclad. >> it's very solid. it's indeed overwhelming. if he's going to have any credibility as president, he needs to stotalking this way. >> reporter: president obama has already retaliated, including

closing two lavish diplomatic retreats and evicting dozens of russian diplomats from the u.s. that plane now moscow bound. trump's team is questioning the white house's motivation. >> so there is a question about whether there's a political retribution here versus a diplomatic response. >> reporter: but even some republicans want more punishment. >> we will be working for much tougher sanctions against russia. they attacked the united states of america. the hacking was an attack. >> reporter: trump says the only way for sure to protect from cyber attacks -- >> if you have something really important, write it out and have it delivered by courier, the old fashioned way. because i'll tell you what, no computer is safe. >> reporter: tonight, dhs is weighing in on new concerns the russians may have targeted the american electrical system. dhs says there are no signs that the hackers penetrated the power grid itself. >>

authorities are investigating a midair crash between two small planes that left three dead. a debris coming down on to a busy shopping center. tonight, questions about which pilot may have been at fault. here's adrienne bankert. >> reporter: at least three dead after two planes collide and fall into a dallas suburb. >> i just don't know there's any chance they could make it. >> reporter: flames and a dark plume of smoke. >> looked like they were doing acrobatic maneuvers. >> reporter: the scene, so tough to watch, you could watch someone in the video telling a little girl to close her eyes. charles drexler shot this

>> they hit so hard, you could tell they were going really fast. >> reporter: the crash happening just a mile from this small airport. there's no one directing traffic, so pilots are on their own. the faa confirming both were operating over visual flight rules. it could take quite a while to complete the investigation because of the two crash sites. one man saying he was taking cover as pieces of the planes fell from the sky. cecilia? >> adrienne, thank you. next tonight, it has been a wild weather start to the new year for millions of americans. in the southeast, heavy rain swamping the gulf coast. more severe weather for texas. winter weather alerts oregon through minnesota, snow at the

seattle airport causing cancellations and delays. and on-deck, an arctic blast that will have us shivering. rob marciano joins us now. you're tracking some rain tonight? >> reporter: across the southeast, it's been rainy from atlanta back through new orleans. and looking for severe weather tonight into tomorrow morning. south of dallas, a couple of pulses of severe thunderstorms. you can see the orange area for enhanced risk. an isolated tornado is possible. and the northwest, seattle, rotating to northern california. and the cold, the lowest since 1979. going to be a cold start to january. cecilia? >> thank you. and did facetime play a role in the death of a 5-year-old girl

marci gonzalez picks up the story from here. >> reporter: tonight, the family of this little girl filing a lawsuit against apple. saying the video calling feature, facetime, is responsible for her death. moriah modisette died in this crash in texas on christmas eve in 2014. the lawsuit claiming the driver, garrett wilhelm, now charged with manslaughter, was using facetime on his iphone when he hit the vehicle modisette and her family were in. attorneys alleging apple had a patent for a feature to block users from using facetime while driving yet never installed it. and never "warned users" of the potential dangers. facetime is not the only app under scrutiny right now. in philadelphia, three young woman killed when their car slammed into a tractor-trailer and burst into flames. family members believe snapchat played a role in the crash.

snapchat telling abc news they have a do not snap and drive warning in the app itself. meanwhile, apple is not responding. at the the time of the crash, there was no statewide law in texas banning the use of cell phones while driving. >> thank you. and we have an update on queen elizabeth's health. prince philip attending church services without his wife. we're told she's recovering from a cold, and today we're told she was up and working. and now to mariah carey's performance on times square, in front of millions. eva pilgrim on what in the world happened out there.

right now, for mariah carey! >> reporter: tonight, mariah carey's meltdown. the ball drop before the ball drop that began innocently enough. ♪ all >> reporter: but no one will forget what happened next. >> just walk me down. >> reporter: the performance spiraling into disaster. >> we can't hear, but i'll get through the moment, okay? >> reporter: mariah carey, standing on stage, not singing. >> we didn't have a check for this song, so we'll just say, it went to number one. >> reporter: carey tried turning it over to the crowd. >> i'm going to say let the audience sing, okay? >> reporter: the pop legend directing her dancers on stage. >> just flip me, because you know how to do it. >> reporter: at one point speaking to the audience while her vocals could be heard. >> i want a holiday too. can i not ve

>> reporter: just when you thought it couldn't get worse -- "we belong together," going to better. millions watching on the abc broadcast. fans blasting the star, tweeting "i tried to sing along to mariah carey, but even mariah carey can't sing along to mariah carey." others showing their support. mariah's explaining the performance with an expletive that stuff "happens." and tonight, in a statement saying her earpiece was not working. right here, you see her fiddling with it. carey's reps say they told the stage managers about the problem but it was not fixed. we asked dick clark productions, they have no comment. cecilia? >> so many people commenting on it, though. thank you. next to the millions of air travelers heading home this holiday, and the objects they leave behind

tonight, what does a 70-inch flat screen have to do with a chain saw? here's gloria riviera. >> reporter: 45 million travelers taking to the skies over the holidays, many of them leaving something behind. check-in, bag drop, security, and those waits at the gate -- a gauntlet to get through with all your belongings. we kind of see it all here. >> reporter: inside the lost and found at denver international airport, wallets, i.d.s, jewelry galore, phone after phone. and, wait for it -- >> people this year left behind a chainsaw, a 70-inch flat screen tv, a ninja blender system, a hoverboard. >> reporter: in miami, a laptop graveyard and bag after bag. not sure how someone forgot this bronze bust or left mona lisa behind. tsa checkpoints are the most common black hole. if you do leave something behind, file a claim with your airline and the airport right away. call the airport lost and found directly. and the more details you can give, the better chance you have at getting your belongings back.

cecilia, there is some hope. in denver, more than 90% of people who filed claims for lost items got them back. cecilia? >> thank you. and there's still much more ahead on this first day of 2017. a pair of protests with high-profile targets raising security questions tonight. also, while we were sleeping, the scene on a rooftop here in new york. police night vision cameras catching a suspect right there on top of a building. liberty mutual stood with me when i was too busy with the kids to get a repair estimate. liberty did what? yeah, with liberty mutual all i needed to do to get an estimate was snap a photo of the damage and voila! voila! (sigh) i wish my insurance company had that... wait! hold it... hold it boys... there's supposed to be three of you... where's your brother? where's your brother? hey, where's charlie? charlie?! you can leave worry behind when liberty stands with you. liberty stands with you™ liberty mutual insurance

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morning. overnight, the iconic 45-foot-tall hollywood sign altered to read "hollyweed." >> it makes you wonder first of all how they did it. it's not my lifestyle but i can still appreciate the creativeness and artistry of it all. >> reporter: artistic, maybe. bold, definitely, but not original. pulling the same prank on new year's day in 1976. crews spending the day fixing the sign. >> well i kind of like the traditional sign, but you know it's kind of cool being here at the moment. >> reporter: two protesters -- one wearing that purple brett favre jersey -- dangling from the rafters of u.s. bank stadium. unfurling this giant banner above the crowd. "divest #nodapl" it read, a rallying cry for those protesting the construction of the dakota access pipeline. >> a whole section of the vikings game got cleared out because of these dapl protesters. >> reporter: the game going on uninterrupted. experts saying the two very public stunts expose lapses in security. >> it just showed people that may want to commit a crime where people are going to get hu

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finally tonight, hitting the road for new year. one family's trip documented in photos, marking their journey over the course of a lifetime. here's john donvan. >> reporter: last year's new year's card from this family, one in a series. began more than 30 years ago, when their dad took them out to a highway for the photo because of a sign. >> i saw the intersection of 79 and 80, i realized that was the perfect place. >> reporter: a year later,

because 1981. a card found its way into the hand of kathy, whom dan had a crush on. >> reporter: then, kathy. >> it was the impetus to call back. >> reporter: and they got married. it kept on going. >> this is life. children grow up. >> reporter: so they showed up in inserts. >> it's brought back the moments in time. happy new year! >> reporter: john donvan, abc news. >> thank you for starting off your new year with us. "gma" first thing in the morning. i'm cecilia vega. i'll be right back here tomorrow night. happy new year from all of us.

>> sensitive and creative. anchor: neighbors and friends try to make sense of a new year's eve loss. a teenage girl shot and killed in her bedroom. after president-elect heads back to new york, the russian diplomats expelled by president obama leave quietly. why it wasn't exactly the timing in mind. now, abc 7 news at 6:30. a tragic beginning to 2017 for a howard county family. a teenage girl shot and killed her bedroom. poli