Nights debate. Do you make the same commitment that you will sir, that you will absolutely accept the result of this election . I will look at it at the time. Im not looking at anything now. Are you saying youre not prepared to stick to that principle . What im saying is, ill tell you at the time. Reporter trump reversing a vow he made just last month. Will you accept the outcome of the election . Reporter Trump Supporters all in, but outside of trumps orbit, a flood of condemnation. When you try to sew the seeds the legitimacy of our elections, that undermines our democracy. I dont believe that theres a rigged election system. Reporter and the North Carolina gop, which said it was not aware Election Results were optional. What donald trump is doing right now is damaging that system, hopefully not beyond repair. Reporter the campaigns new spin, al gore did it too. But back in 2000, gore never questioned the integrity of the process before the ballots were cast, and the recount was law, given how close the race was. Trumps campaign staking its candidacy on easily refuted claims, from the rigged election, trumps iraq war stance, and russian hacking. She has no idea. Its time for you to stake a stand. Whether its russia, china, or anybody else. Reporter today the Intelligence Community pushing back hard. Director of National Intense reasserting russia was behind the wikileaks hack. When we say were confident, you know, i think its for itself. Reporter nbc news has learned from government sources trump was even briefed on russias involvement with the hack in his National Security briefings, three weeks after he openly asked putins government to find clintons missing emails. Russia, if youre listening, i hope youre able to find the 30,000 emails that are missing. Reporter less than 24 hours after that contentious debate, both donald trump and Hillary Clinton will be here, attending the alfred e. Smith dinner, where the only thing separating them will be a priest. Cardinal timothy dolan, seating right between them. All right, katy tur, thanks. A potentially tense and awkward affair certainly after what happened on that stage last night. At times, things got personal. Heated moments that included the kind of namecalling weve never quite heard in a president ial debate before. We get more on that from nbcs andrea mitchell. Reporter it was downright shes been proven to be a liar. Rather have a puppet as president. No puppet, youre the puppet. Reporter fight night in vegas where the biggest impact white be on the critical female swing voters. Donald trump using graphic language to fire up conservatives, attacking Hillary Clinton on abortion. Based on what shes saying and based on where shes going and where shes been, you can take the baby and rip the baby out of the womb in the ninth month, on the final day. Acceptable. Reporter clinton relishing her first chance to go after trump about his female accusers, looking to get under his skin. Hes said he could not have possibly done those things to those women because they were not attractive enough i did not say that. For them to be assaulted. I did not say that. Reporter trump returning fire. She mentions this, which is all fiction. All fictionalized, her and her very sleazy campaign. But i will tell you what isnt fictionalized, are her emails. Reporter then the moment the clinton team was hoping for. Such a nasty woman. Reporter how did you feel when he said, nasty woman, nasty woman, and youre a puppet. I just didnt pay any attention to that. Reporter it quickly turned into a meme on twitter compared to a Janet Jackson so hit from the audience. Nobody has more respect for women than i do. Nobody has more respect please, everybody. Reporter late today, michelle obama, clintons best surrogate, going after trump too. Decent men do not demean women, and we shouldnt tolerate this behavior from anyone man, let alone a man who wants to be president. Performance last night that leads me to believe hes going to do any better among women voters than hes doing right now. Reporter with only 19 days left, the Clinton Campaign cannot hide its glee, because they believe theres not enough time for trump to bring those women voters back to his side. Turning now to nicole wallace, you are a veteran of tough campaigns. Trump needed a breakthrough night last night. Did he harm himself, especially lester. The poll numbers that were up at the end of andreas piece tell you everything you want to know, if you want to know whether a republican can win a national election. The last time it happened, was 2004. George w. Bush did that by narrowing that gender gap. He got the married women, he got the mom vote, something ive been tracking during the general election. And donald trump pushed them much further away. We have to take into account that we dont always hit the the belt way, but calling her a nasty woman, interrupting her the whole time, essentially morphing into the snl caricature of himself really sets in as a terrible image for donald trump among the kinds of voters he needs to sway. But think about the first 30 minutes of the debate. A much more subdued donald trump, and getting substantive issues, supreme court, very important to voters. Yeah. At that point, did you think he could turn this around . Well, it was his best he said last night, it was also her best debate. So shes almost in another league, in terms of her ability to communicate and now defend her own ideas. So i think she did a better idea. She has vulnerabilities too. These are the two most unpopular candidates weve seen on either side, as chuck todd keeps reminding us. While we got off to a solid start for him, he just didnt this point. Nicole, thank you very much. Turning now overseas where a u. S. Service member was killed in iraq today by a roadside bomb. The First American to die in the u. S. Backed offensive to drive isil out of mosul. Tonight our Richard Engel is on the front lines with iraqi forces and brings us an extraordinary look at the underground Tunnel Network isis used to prepare for this battle. Reporter iraqi and kurdish their biggest push toward mosul. The main offensive was from the east and to the town of bartella, just over ten miles from the city. We climbed into one of the Iraqi Special forces old american humvees. Its battleworn, shot up, and the driver said damaged by an isis suicide bomber today. Then it was on foot. Quickly, because rounds whizzed by. This predominantly isiss main defensive positions leading towards mosul, and theyre fighting hard to keep it. Isis sending out car bombs. But iraqi troops are advancing faster than u. S. Commanders anticipated. Well be in mosul in two days, a soldier boasted. But isis has had two years to prepare for this fight. The soldiers showed us a tunnel they had just found. This was an isis escape route. Also seems to be like isis fighters lived here, safe from u. S. Warplanes. Just based on the number of mattresses weve seen, this could have held, 20, maybe 50 people, more if they packed them in. The tunnel extended for about a half a mile. At the far end, we came up into what appeared to have been an isis headquarters. Food still in the kitchen area. Halfmade bombs too. And chemicals for more. On the walls, isiss the sight of the black flag was once enough to send the iraqi army running. Thats how isis took mosul. Now its isis on the run. Tonight, iraqi forces have taken bartella, putting them within striking distance of mosul. Lester . Richard engel in iraq tonight, thank you. In arizona, this evening, police have released 911 calls connected to an unsolved serial killing spree that is still baffling investigators. After at least nine separate shootings, seven people, have been killed in the phoenix area. There have been thousands of new leads, but no arrests. We get the latest from nbcs miguel almaguer. Phoenix 911, where is your emergency . Um, hes shot on the floor. Yes, its my brother. Hes been shot. Reporter the heart breaking call for help from one family targeted by arizonas serial killer. They pulled up in front of our house, i guess, and they im inside with my kids. I have two babies. Reporter after seven people were killed, including a 12yearold girl, Phoenix Police now releasing chilling 911 calls, hoping to generate new leads in a case gone cold. Nancy pena, who lost her brother horatio, cant bear to listen to the calls. These families are having to rehear it, relive it. Its gutwrenching. Reporter the killing spree began in march. Sketches but no arrests in this community on edge. He comes up at night. You get out of your car, he shoots you. Reporter a 75,000 reward and more than 3,000 tips, but the sketch, the only solid lead. When you see someone as prolific as this shooter, or these shooters have been, i think Law Enforcement knows its highly likely they could strike again. Reporter tonight investigators hoping for a break they have the face of a killer. All right, how old is he . Hes only 21. Reporter and now the sound of the heartbreak hes left behind. Miguel almaguer, nbc news. There is late word this evening of another death connected to those exploding takata air bags. The national Highway Traffic Safety Administration says a 50yearold woman died from injuries in a crash on september 30th, while driving a honda civic that was first recalled in 2008. The repair never completed. The 11th confirmed u. S. Fatality bag inflators. Still ahead tonight, every homeowners nightmare. The foundation of your house crumbling under your feet. Why its happening to so many homes and why its time to doublecheck your insurance policy. Also buyer beware. Why apple says its time to think twice before shopping for ba alert. In connecticut, as many as 30,000 homes are facing an issue so serious that the governor wants fema to declare it a natural disaster. And the effects could cost up to a billion dollars. Homeowners are watching their concrete basement walls crumble, putting their houses at risk of collapse in what could be a wakeup call for people everywhere, the Insurance Company say the problem isnt covered. Heres nbcs stephanie popping noises downstairs. And in the middle of the night. Reporter the noises were so strange they had no idea what was going on. Until vince went down to the basement. Oh, my god. And this has probably happened in the past year. Reporter the middle of the night sounds were the walls of the basement splitting. You can see outside. Reporter in some places, wide open. Are you worried at night the house is going to come down on top of you . I worry. I do worry. How do you sleep . Some nights its hard. House was built 30 years ago, and theyre not alone. Theres something rotten in the foundations in northeastern connecticut. Engineer bill neil has told hundreds of families their homes are unsafe. Reporter do you have any sense the scale of this problem right now . Say is pob is a mineral called purr type. Found in the query. After years of exposure to water. It expands, causing the cracks. There is a fix. Lifting the home completely off the foundation. And pouring a new one. For them, they the price tag is more than 200,000. Nearly 60 the value of their home. They turned to their homeownes insurance. The claim was denied. An industry Spokesman Says basically Home Insurance doesnt cover the problem. Loss is occurring because of defective Construction Materials and or shoddy wormmanship. No matter what state you go to, Home Insurance is not going company. Meanwhile the house continues to crumble. People i talk to and say why dont you just move out, well, its my home. On top of the emotional pain, this family and many like them face financial ruin and theres little hope of a quick solution. Nbc news, willington connecticut. Back in a moment with why snoopy, charlie brown, and the rest of the peanuts gang are down a gig were back in a moment with apple says buying chargers and cables labelled as genuine apple products on amazon and found nearly 90 of counterfeit. Apple warns the knockoffs pose a significant risk of overheating, fire, and electrical shock. Mobile star did not respond to our request for a comment. And good grief, snoopy just got canned. Metlife is saying goodbye to the the move comes as the company spins off most of its u. S. Insurance operations, instead focusing on corporate and international business, marking the end of an era for snoopy. Soon america will have to say byebye to bao bao, the giant panda born in washington, d. C. Three years ago. Her parents were on loan from china and, under that agreement, shell be sent to china early next year. The atlanta zoo also panda twins will be sent to china in two weeks. When we come back, a team whose unbreakable bond with her younger brother has inspired a potentially lifesaving mission. Finally tonight, we have a remarkable story about the bond between a teenage girl and her little brother. A love that remains so strong even through tragedy and now theyve inspired a project that could help millions of other families. Heres gadi schwartz. . Id like to make myself . . Reporter at age 7, tanner long street helped put blush on his sisters cheeks. At 8, he was her dancing partner. Tanner, dance the age of 10, tanner was diagnosed with brain cancer and died the next year. I didnt do anything, was the words that came out of his mouth. Reporter tanner had a mutated gene, called tp53, that can lead to deadly cancer. When tested, the same gene showed up in his father and his sister. What are your chances of getting cancer . Numbers wise, its over 90 . I couldnt be more proud of someone who fas reporter now casey is the sole subject in a groundbreaking dna study theyve named the tanner project, in memory of her brother. I think shes a great example for the world. Reporter shes working with doctors like craig vinter, the first person to sequence the human genome. Pioneers like casey help us because well find out from all the tests, whether shes good evening. Our big story, the first lady making a huge push for Hillary Clinton in the valley. Thousands of people are pouring into the Phoenix Convention center today asthma shell obama made her case on why our state should turn blue this election. President bill clinton is the only democratic nominee who years, but this election is coming down to the wire for donald trump and Hillary Clinton. Jo brahm resnik has more. Reporter michelle oh billiona capped the Clinton Campaigns oneweek blitz of arizona with a relentils attack on donald trump. First Lady Michelle obama was a rock star for the 7,000 people crammed into the phoenix her opponent has tweets. You decide. Reporter mrs. Obamas mission, firing up the crowd for Hillary Clinton and shutting down republican nominee donald trump. We have a candidate whose vision for our country is completely and utterly lacking in hope. Reporter trumps comments during wednesdays final president ial debate were still fresh. And when a president ial candidate threatens toic nor our voices and outcome of this election, he is threatening the very idea of america itself. Reporter the first lady also called out trump for his comments about women. He demeans and humiliates women as if were objected meant solely for pleasure and entertainment rather than human beings worthy of love and respect. Reporter that struck a chord with Katherine Mendez at the rally with son daigle. The first lady is a great