walking their houses crack apart. an alarming wake-up call for homeowners everywhere. "nightly news" begins right now. from nbc news world headquarters in new york, this is "nbc nightly news" with lester holt. good evening. donald trump who has repeatedly decried negative media coverage of him, as part of a rigged system, has once again made himself the top of the news cycle for going wheo has gone before. at aeral ne ohio today, trump first mocking and then trying to qualify his jaw-dropping response from last night's debate, about whether he would accept the outcome of the election. his refusal to say managed to irk even some of his most ardent supporters, while shifting the focus from what many believe was his best debate performance. nbc's katy tur leads off our coverage. >> ladies and gentlemen, i want to make a major play by the rules. >> -- that i will totally accept the results of this great and historic presidential election, if i win. >> reporter: making it clear the only outcome he will accept is the one that puts him in the white house. >> i would also reserve my right to contest or file a legal challenge in the case of a >> reporter: a defiant doubledown from last night's debate. >> do you make the same commitment that you will absolutely -- sir, that you will absolutely accept the result of this election? >> i will look at it at the time. i'm not looking at anything now. >> are you saying you're not prepared to stick to that principle? >> what i'm saying is, i'll tell you at the time. >> reporter: trump reversing a vow he made just last month. >> will you accept the supporters all in, but outside of trump's orbit, a flood of condemnation. >> when you try to sew the seeds of doubt in people's minds about the legitimacy of our elections, that undermines our democracy. >> i don't believe that there's 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 campaign's new spin, never questioned the integrity of the process before the ballots were cast, and the recount was automatically triggered by state law, given how close the race was. trump's campaign staking its candidacy on easily refuted claims, from the rigged election, trump's iraq war stance, and russian hacking. >> she has no idea. >> it's time for you to stake a stand. >> whether it's russia, china, or anybody else. >> reporter: today the intelligence community pushing back hard. russia was behind the wikileaks hack. >> when we say we're confident, you know, i think it's speaks for itself. >> reporter: nbc news has learned from government sources trump was even briefed on russia's involvement with the hack in his national security briefings, three weeks after he openly asked putin's government to find clinton's missing e-mails. >> russia, if you're listening, i hope you're able to find the 30,000 e-mails that are >> reporter: less than 24 hours after that contentious debate, both donald trump and hillary clinton will be here, attending the alfred e. smith charity 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 before. we get more on that from smbs's andrea mitchell. >> reporter: it was downright brutal and personal. >> she's been proven to be a liar. >> rather have a puppet as president. >> no puppet, you're the puppet. >> reporter: fight night in vegas where the biggest impact white be on the krital female swing voters. donald trump using graphic language to fire up conservatives, attacking hillary clinton on abortion. >> based on what she's saying anded where she's been, you can take the baby and rip the baby out of the womb in the ninth month, on the final day. and that's not acceptable. >> reporter: clinton relishing her first chance to go after trump about his female accusers, looking to get under his skin. >> -- he's said he could not have possibly done those things to those women because they were not attractive enough -- >> i did not say that. >> reporter: trump returning fire. >> she mentions this, which is all fiction. all fictionalized, probably, possibly started by her and her very sleazy campaign. but i will tell you what isn't fictionalized, are her e-mails. >> 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 >> i just didn't pay any attention to that. >> reporter: it quickly turned into a meme on twitter compared to a janet jackson song. trump even taking a hit from the audience. >> nobody has more respect for women than i do. nobody has more respect -- >> please, everybody. >> reporter: late today, michelle obama, clinton's best surrogate, going after trump too. >> decent men do not demean women, and we shouldn't tolerate this behavior from prt. >> there's nothing that i saw in his. approxima performance last night that leads me to believe he's going to do any better among women veerts than he's doing right now. >> reporter: with only 19 days left, the clinton campaign cannot hide its glee, because they believe there's not enough time for trump to bring those women voters back to his side. turning now to nicole ac are a veteran of tough campaigns. trump needed a breakthrough night last night. did he harm himself, especially with women, though? >> oh, just a little, lester. the poll numbers that were up at the end of andrea's 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 i've further away. we have to take into account that we don't always hit the mark in terms of understanding what resonates beyond 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 very important to voters. >> yeah. >> at that point, did you think he could turn this around? >> well, it was his best performance. it was his best debate, but as he said last night, it was also her best debate. so she's 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 weech seen on either side, as chuck todd solid start hefor him, he just didn't close the deal with anybody who's undecided at 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 this battle. >> reporter: iraqi and kurdish forces today launched 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. it's battle-worn, shot up, and the driver said damaged by an isis suicide bomber quickly, because rounds whizzed by. this predominantly christian village and one of isis's main defensive positions leading towards mosul, and they're fighting hard to keep it. isis sending out car bombs. but iraqi troops are advancing faster than u.s. commanders anticipated. we'll be in mosul in two days, a soldier boasted. but isis has had two years to prepare for this fight. the soldiers showed us found. this was an isis escape route. also seems to be like one of their positions. isis fighters lived here, safe from u.s. warplanes. just based on the number of mattresses we've 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 and chemicals for more. on the walls, isis's infamous logo. the sight of the black flag was once enough to send the iraqi army running. that's how isis took mosul. now it's 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 cal unsolved serial killing spree that is still baffling investigators. after at least nine separate shootings, seven people, including a child, have been killed in the phoenix area. there have been thousands of new leads, but no arrests. we get the latest from nbc's miguel almaguer. >> phoenix 911, where is your emergency? >> um, he's shot on the floor. yes, it's my brother. he's been shot. >> reporter: the heart breaking call for help serial killer. >> they pulled up in front of our house, i guess, and they shot him when he got out of the car. i'm inside with my kids. i have two babies. >> reporter: afterseven people were killed, including a 12-year-old 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, can't bear to listen relive it. it's gut-wrenching. >> reporter: the killing spree began in march. witnesses helped generate 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 >> reporter: tonight investigators hoping for a break in the case. they have the face of a killer. >> all right, how old is he? >> he's only 21. >> reporter: and now the sound of the heartbreak he's 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 50-year-old woman died from injuries in a crash on september honda civic that was first recalled in 2008. the repair never completed. the 11th confirmed u.s. fatality tied to ruptures of takata air bag inflators. still ahead tonight, every homeowner's nightmare. the foundation of your house crumbling under your feet. why it's happening to so many homes and why it's time to i'm terrible at golf. he is. but i'd like to keep being terrible at golf hmb plus 20 grams of protein to help rebuild muscle. for the strength and energy to do what you love. new ensure enlive. always be you. our special today is the seared ahi tuna. don't you hate that? when they don't tell you how much something costs and you have to ask? maybe that's why i always make sure to... ... ?bring up the costs associated with your services.? i know. transparency about costs. back now with a consumer 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 wake-up call for people everywhere, the insurance company say the problem isn't gosk. >> we started hearing 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. e going to come down on top of you? >> i worry. i do worry. >> how do you sleep? >> some nights it's hard. >> reporter: their house was built 30 years ago, and they're not alone. there's 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? >> reporter: in every case, the problem is traced back to one local quarry and the same concrete company, j.j. moves. in a statement, they raise the possibility that the concrete was installed improperly by contractors, but experts say it's a mineral in the quarry. after years of exposure to water and oxygen, it expands, causing the cracks. there is a fix. foundation and pouring a new one. for the parokios who raised four children here, the price tag is more than $200,000. nearly 60% the value of their home. so they turned to their homeowner's insurance. the claim was denied. an industry spokesman said basic homeowners insurance doesn't cover the problem. >> the loss is occurring because of defective construction materials and or shoddy workmanship. no matter what state going to be paid out. >> reporter: they're suing their insurance company. meanwhile, their house continues to crumble. >> people say, why don't you just move out? well, it's my home. >> reporter: many of them face financial ruin and there's little hope of a quick solution. stephanie gosk, nbc news, willington, connecticut. we're back in a mome ? 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let me show you something better. the capital one venture card. with venture, you earn unlimited double miles on every purchase... not just...(dismissively) airline purchases. every purchase. everywhere. every day. no really! double miles on all of them! we're back with a warning for online shoppers. 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 and good grief, snoopy just got canned. metlife is saying goodbye to the beloved character. 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 bye-bye to baobao, the giant panda born in washington, d.c. three loan from china and, under that agreement, she'll be sent to china early next year. the atlanta zoo also announced its 3-year-old giant panda i had frequent heartburn, but...my doctor recommended prilosec otc 7 years ago, 5 years ago, last week. just 1 pill each morning. 24 hours and zero heartburn, it's been the number 1 doctor recommended brand for 10 man: i accept i'm not the deep sea fisherman i was. i accept i'm not out on the ocean wrestling marlin. i even accept i have a higher risk of stroke due to afib, a type of irregular heartbeat not caused by a heart valve problem. but i won't go after anything with less than my best. so if i can go for something better than warfarin, i'll do that too. eliquis. eliquis reduced the risk of stroke better than warfarin. plus, it had significantly less major bleeding than warfarin. that's what i wanted to know. don't stop taking eliquis unless your doctor tells you to, as stopping increases your risk of having a stroke. eliquis can cause serious and, in rare cases, fatal bleeding. don't take eliquis if you have an artificial heart valve or abnormal bleeding. while taking eliquis, you may bruise more easily. and it may take longer than usual for any bleeding to stop. seek immediate medical care for sudden signs of bleeding, like unusual bruising. eliquis make increase your bleeding risk if you take certain medicines. i may not be going for the big one, but i'm still going for my best. and for eliquis. reduced risk of stroke, plus less major bleeding. ask your doctor if switching to eliquis is right for you. 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 they've inspired a project that could help millions of other families. here's gadi schwartz. ? i'd like to make myself ? >> reporter: at age 7, his sister's cheeks. at 8, he was her dancing partner. >> tanner, dance! >> we were so close. >> reporter: but at the age of 10, tanner was diagnosed with brain cancer and died the next year. >> i didn't do anything, was the words that came out of his mouth. >> reporter: tanner had a mutated gene, called tp-53, that can lead to deadly cancer. when t father and his sister. >> what are your chances of getting cancer? >> numbers wise, it's over 90%. >> i couldn't be more proud of someone who faces what she faces. >> reporter: now casey is the sole subject in a ground-breaking dna study they've named the tanner project, in memory of her brother. >> i think she's a great example for the world. >> reporter: she's working with doctors like craig vicinitier, the first person to help us because we'll find out from all the tests, whether she's develops something early on, or whether she never develops it. >> reporter: scientists are figuring out how she can live with the same genetic mutation that took her brother's life. >> i'm used to it. >> reporter: they're also monitoring for the earliest signs of disease. >> everything looks good. >> reporter: so far, no cancer. which means she's free to be a normal project to encourage others to consider genetic testing. >> he taught me so much. he's the reason why i am who i am today. i love you. >> reporter: a bond with her little brother that remains unbroken. gadi schwartz, nbc news, los angeles. >> what a great story. that's going to do it for us on a thursday night. i'm lester holt. for all of us at nbc news, thank you for >> he is dangerous and he is still out there. coming up went on lock down as police searched for a man who attacked a woman and attempted a carjacking. plus, recognition for the lightning. the news starts in a minute. i'm a republican, but this election is so much bigger than party. my son max can't live in trump world. so i'm crossing party lines and voting for hillary. i don't always agree with her, but she's reasonable. be able to tell my kids that i did the right thing when it really mattered. i'm hillary clinton and i approve this message. >> right now on newschannel8 at 7:00. >> good evening, venice police