Have to recuse himself and tonight nbc news has word on when Robert Mueller may finish his investigation. The major airport closed down, fears of drones hitting airplanes. Over 100,000 travelers impacted. The hunt tonight for those responsible. Shocking video, the father celebrating a backyard Holiday Party struck and killed by a stray bullet. The mystery gunman at large. Is this the most festive street in america . The holiday display you have to see. Announcer this is nbc nightly news with lester holt. Good evening, everyone. Breaking news tonight, defense secretary james mattis is stepping down leaving a white house increasingly gripped by chaos and erratic upheaval. The last of the senior military officials President Trump brought into his administration and frequently called his generals. Mattis tonight tendering a twopage Resignation Letter pointing to disagreements with the president about the use of military power and a thinly veiled rebuke of mr. Trumps treatment of american allies. Kristen welker begins our coverage. Pretty significant news here. Reporter lester, this is a bombshell, both secretary mattis and the white house acknowledging the policy differences between mattis and the president played a key role in his departure. The move has implications for Americas National security and foreign policy. One senior official says quote, the wheels are coming off. He was one of my generals, tonight general james mattis is on his way out. The president tweeting late tonight, general jim mattis will be retiring with distinction at the end of february after having served my administration as secretary of defense for the past two years. The announcement comes a day after the president announced to withdraw plans from syria. They were also at odds after President Trump asked the military for plans to withdraw troops from afghanistan. Tensions have been simmering for months and trump seemed to criticize mattis in a recent interview. I think hes a democrat. Reporter in a lengthy Resignation Letter mattis said the president deserved a secretary of defense hossa lines were better aligned with his, a reference to the riffs he had with mr. Trump over mr. Trumps treatment of historically strong allies. Mattis was among the president s first cabinet picks. General mad dog mattis. Reporter and now he joins the ranks of departed top officials within the trump administration. The president tweeting, a new secretary of defense will be named shortly. Kristen welker, nbc news, the white house. Im Andrea Mitchell in washington where the president s plans for afghanistan and withdraw from syria were the final straw. A decision mattis strongly opposed and so had the president s key advisors arguing the fight against isis was not over. It would be reckless. With regard to stabilization, we have a long way to go. Reporter to the president , its a Campaign Promise kept tweeting today does the u. S. Want to be the policeman of the middle east . Mattis among those who thought they talked him out of it and then big pressure from turkeys president erdogan three weeks ago and on a call friday, arguing americas partners in the fight, syrian kurds are terrorists. The president over ruling secretaries of state and defense announcing his decision with a slick white house video invoking the sacrifice of u. S. Troops. We won and thats the way we want it and thats the way they want it. Hes not qualified to invoke the sacrifice or to invoke the memory of those magnificent troops. Reporter angry republicans pleading with mr. Trump to change his mind. And this war you will not win by quitting, by giving up. This is akin to surrendering. Reporter allies long viewed mattis as the grown up in the room, a guardrail for a president they believe is not reliable for foreign policy. Thank you. There is much more drama were watching in washington as key parts of the u. S. Government should shut down late tomorrow after President Trump rejected a compromised funding deal to avoid a holiday shutdown. Our Hallie Jackson has details. Reporter the shutdown scrambles back to square one. Any measure that funds the government must include border security, has to. Reporter that torpedos the shortterm fix the Senate Passed overnight that did not include money for the wall. All in favor say aye. Aye. It seemed like the president would still sign it until the roar from typically loyal conservatives. This is a hill we should be willing to die on. Help our president build the wall like we said. Reporter by midday, message received. The president informed us he will not sign the bill. Reporter so hes sending lawmakers back to the drawing board, the problem is he doesnt have the votes for what he wants. In terms of wall funding, thats a nonstarter. Reporter now three options. One, the president changes his stance. Unlikely. The president has gotten word to me that he is either getting funding for the border or he is shutting the whole thing down. Reporter option two, lawmakers change their stance. Also, unlikely. Option three, nobody changes anything. Shutdown and no paycheck for hundreds of thousands of federal workers. Dont shutdown the government, you know. We need the government. Dont shut it down. Reporter no matter what, the president will break a campaign pledge. He said mexico would pay for a wall but now he wants taxpayers to, threatening a shutdown if congress doesnt agree. An iraq war veteran has a solution, try to raise 1 billion on the internet. Up to 7 Million Dollars so far. Hallie jackson, nbc news the white house. A call by ethics officials ruling that acting attorney general Matt Whitaker will not have to recuse himself in the russia probe. That has democrats furious after whitakers pass criticism of the mueller investigation, and that has been the dark cloud who have verying over the Trump Presidency from the start but it is just one of several growing avenues of potential legal parol for President Trump and a sitting president breathtaking in their scope if not historic. Tonight justice correspondent Pete Williams with where they all stand and what may becoming next. Reporter sources familiar with the plans of Robert Mueller who is working inside this washington, d. C. , office from the Justice Department predict hell finish his report as early as mid february. They expect hell answer the question given to him 18 months ago, were there any links or coordination between the russian government and Trump Campaign to influence the election. Its unclear whether mueller will touch President Trump himself. Legal experts believe mueller has had trumps tax returns. Already the legal battle engulfed four people that worked on the Trump Campaign and potentially worse for the personal lawyer Michael Cohen in two controversial felonies from hush money payments to two women. It could turn out to be a continuing legal headache for the president looking into financial dealings of those of his companies and members of his family analyzing trump tax returns and credit reports. What type it is of leads do they give you . Financial leads. Where is the money coming from and going . And oh, by the way, its not that hard to get. Reporter the president insisted there never were conflicts between his business interest and the nations foreign policy. I have nothing to do with russia. To the best of my knowledge, no person i deal with does. Reporter Michael Cohen, the former trump lawyer, says dealings with russian officials about a trump tower continued well into the campaign and mr. Trump knew about them. New York Attorney general forced the foundation to shutdown and give away the remaining assets calling it a little more than a checkbook for mr. Trumps business and political interest. The attorney general of maryland in washington d. C. May seek trumps tax records. They claim his ownership of the trump hotel violates the constitutions ban on Public Officials getting foreign financial benefits. They say it patronizes the hotel benefitting him personally. No other president has ever run a business and actually sought business from foreign sovereigns and domestic sovereigns while being president. Reporter as for muellers core mission, he is said to be orchestrating a Media Campaign in the u. Sms. And using fake sites and mueller charged russian Intelligence Officers with hacking into democratic computers to steal and leak thousands of Campaign Email s and President Trump says mueller has come up entry. There is no collusion. You know why it will be fine . There is no collusion. Reporter the coming weeks will provide answers to lingering questions, what happened at the june 9th meeting in trumps tower with russians offering derogatory information about Hillary Clinton and did anyone in the Trump Campaign help the russians get and spread the hacked emails. What does it mean for donald trump . Very likely not criminal charges experts believe and impeachment is unlikely with republicans controlling the senate and as the mueller team shuts down, democrats will take control of the house reenergizing congressional investigations of the campaign and white house with the final revelations from Robert Mueller yet to come. Pete williams, nbc news, washington. Turmoil and confusion in the Nations Capital over a potential Government Shutdown factored into a dismal day on wall street. The dow plunging over 460 points amid the uncertainty and the fed raising interest rates. Ann thompson on what it all means. Reporter the chaos in washington infecting wall street. The low, we were down almost 700. Reporter sending the dow on a roller coaster of its own today. Todays sell off, the market is having the worst december since the great depression. Reporter on the heels of the red fell reserve raising the interest rate, the dow closing down 464, losing an astonishing 1700 points since friday. The tech heavy nasdaq flirting with bare market territory, finishing just shy of a 20 drop from the august peak. Why is the market so negative . Because of uncertainty. Largely caused because of things like a trade war and policies they dont understand. Reporter and fears of an economic slowdown giving investors a bad case of the jitters they cant shake. Ann thompson, nbc news, new york. Lets turn to the massive storm hitting at the worst possible time as one in three americans is traveling for the holidays. Heavy rain, strong winds making for treacherous travel in a lot of places. Here is nbcs tom costello. Reporter heavy rain and a bumper to bumper as the Holiday Travel week shifts into high gear. Getting drenched a spaghetti map of some of the nations busiest highways heading east, west, north, south. I95, 75, 55, 40, 70 and ia on the west coast. In tampa a line of storms damaged 70 homes, one injured. Nasty weather that Michelle Joyce and their family are preparing to brave starting a road trip in georgia to family in florida. Survival mode. Lets get there peacefully, safely and just, you know, have a happy, jolly good time. Reporter meanwhile, the rain complicating air travel. 150 cancellations and 4,000 delays. 19 still missing. Reporter at the brandnew American Airlines control center in dallas, hd cameras provide a 180 view of every runway, ramp, caterer and gate. Every plane arriving tracked by gps. What that gives us is a realtime information where that airport is on the field along with where it is in its in route phase. Reporter nationwide the tsa expects to screen a Record Number of travelers this holiday, close to 2. 7 Million People each day through saturday. Tsa is urging travelers take your carry on liquids and gels and food and put them in a separate plastic bag so you dont slow down the checkpoint. The worst of the travel delays should be out of here by tomorrow night. Lets get to al roker. Al, take us through the impact of the storm tonight into tomorrow. Its reached here in new york, lester, and its causing a lot of damage down south, heavy rain weve got severe thunderstorm watches stretching down through southern florida and that heavy rain makes its way to the north. Here are the impacts today. We got Severe Weather for 9 Million People. Threat of tornados from florida to the carolinas. Heavy rain upwards of two to three inches of rain especially in the northeast, coastal flooding during high tides and the winds are going to be a big factor, lester. Through tomorrow again causing big problems for the airports and high profile vehicles on the roads, wind gusts of 50 to 60 miles per hour. Lester . Got to be nasty out there. Al roker, thanks. Were dealing with travel headaches at home, a much different threat shut down one of the busiest airports overseas. Flights are grounded as authorities try to catch whoever is deliberately flying drones over the air field. Bill neely has details. Reporter going nowhere, more than 100,000 passengers with flights cancelled, delayed by at least one rogue drone deliberately and repeatedly flown near the runway at london gatwick, one of europes busiest airports. Police snipers deployed to take it down. Troops called in to hunt for the operator. This crime impacted such a huge number of people. Reporter passengers stuck for hours. They should have taken control of the airport by now, i think. Reporter the drone danger is clear globally. Last week an aero mexico flight was hit by a possible drown as it landed damaging the nose and radar. In the u. S. , more than 2,000 drone sightings were reported by pilots this year. If it were close to the ground, it could result in loss of the airplanes. The drone threat is very, very real. Reporter the police say this isnt terror related though that risk from drones is very real, too. This airport will be a mess for days, the drone problem, though, will be with us all for much longer. Lester . Bill neely in london, thanks. A judge in new york today ruled the Sexual Assault case against Harvey Weinstein can go forward. His lawyers argue that the indictment should be thrown out. Marissa tomey and actresses appear to support weinsteins accusers. He denies the charges. Also tonight, caught on camera, a stray bullet strikes and kills a father at a Holiday Party. Then, new video of a massive explosion that left a firefighter dead. And the miracle on 34th street but not the one in new york. Police in florida are searching for the gunman that fired a bullet that struck and killed a husband at a Holiday Party. Gabe gutierrez has the story. We want to warn you the video video is disturbing. Reporter the music was blaring at this Holiday Party in miamidade county, florida. The 40yearold man had just walked in and sat down to hear karaoke when all of a sudden he slumps down and desperately reaches for the man next to him. The music continues to play and fellow party goers seem to have no idea what happened but quickly realize something is horribly wrong, maybe heart attack but turns out a stray bullet had pierced his chest, hes rushed to the hospital where he later dies. Police say the bullet didnt come from anyone at the party, instead detectives think it came from across a lake that boarders the backyard. Could be somebody cleaned their gun and accidental discharge or somebody could have been shooting up in the air from somewhere else. Reporter one neighbor says hes heard random gunshots in the area for years. I no longer even go into my backyard anymore for fear of getting hit he says. Tonight his family is pleading for answers wondering why this stray bullet chose him. Gabe gutierrez, nbc news. All right. There is more to tell you about tonight. Coming up, the dramatic video of a deadly explosion. From wisconsin tonight, dramatic video of a deadly gas explosion that levels part of a quiet town. Our Miguel Almaguer has details. Reporter dashcam captured the massive explosion. The blast so powerful, several buildings were obliterated. Wisconsin firefighter cory barr was killed. Today, officials releasing this new video of the july and explosion. Investigators have determined no criminal charges will be filed after a construction crew mistakenly tore into a gas line. What happened here was deadly miscommunication but not a crime. An accident that should have been prevented, but could have happened anywhere. Miguel almaguer, nbc news. After the break, the Christmas Spirit and the miracle on another 34th street. Punished. The video content causing turmoil in the department. Plus driving solo in the carpool lane is a perk you may be about to lose. The new requirements that will kick some drivers out. Next. In tonights snapshot, the miracle on 34th street but probably not the one that comes to mind first. Its a light show that brings in families far and wide to see. Here is catie beck. Reporter winter feels warmer on 34th street in baltimore. It has for more than 30 years. This time of year families with stand the cold to stand beneath the lights. I like the one behind us. Reporter row houses dripping with decoration, each its own ornament. To see the little ones and face in awe. Reporter darlene and bob are the elves behind it. It turns out, the spirit was contagious. I like decorating for christmas. Whether all these people show up or not, id still do it. Reporter from hub cab Christmas Trees to flamingos, eyes of all ages gaze in wonder. It doesnt feel like christmas until you come here. It makes you feel jolly and happy and really get into the spirit. Seeing these lights turn on is total christmas cheer. Reporter a gift to the community but also one for those who live here. Just to see those smiles and know you made somebody happy for a few minutes is worth it. Reporter catie beck, nbc news. Merry christmas. Looks like its worth checking out, bright and cheery block. Thats nbc nightly news for this thursday. Im lester holt, for all of us, right now at 6 00, gone in seconds. What thieves put in the back of that truck that makes this crime a felony. But first, only on nbc bay area, the salacious tape that has one Police Department under the microscope. A Police Sex Scandal in the heart of silicon valley. Two rookie officers have been fired and two veteran officers in trouble. Damian trujillo broke this story in sunny vail with the exclusive story. Reporter im told these allegations are reverberating throughout the department. The female officer allegedly in that video has been on the force for a year and a half and now is in the center of a huge controversy here in sunnyvale. The allegations are stunning. Sources say the female officer made a porn video with her husband while she was a cop in hawaii. They allegedly streamed it live on porn hub. Com. It