Moment, but we begin here this evening because its the focus of so much of the world. This is the eve of what may be the largest gathering of heads of state ever, anywhere in the world. And of course, its all for Nelson Mandela. He will come to lie in state at the Union Buildings behind us here in the capital city of pretoria. The outpouring has been so great since his death, the number of dignitaries arriving here is so large, this nation is going to be pushed to capacity in terms of crowd control and transportation and accommodations and security, starting really when the sun comes up tomorrow. They are scrambling to accommodate president s and kings and citizens. All while this country remains, of course, in mourning for this global figure that they happen to share with the world. So we will begin our coverage tonight with nbcs lester holt. He is just to the south of us outside the mandela home in soweto, the township where tomorrows service will take place. Lester, good evening. Reporter hey, brian. Good evening. You have to believe the largest stadium on the african continent isnt big enough to accommodate all those who would like to say farewell to Nelson Mandela. That guest list is impressive. It ranges from afghanistan to zimbabwe. There are alist celebs here as well. A hujs security challenge, yes, but a testament to Nelson Mandelas global influence. The appearance of the man they call madiba reporter it was at the fnb stadium Nelson Mandela made his last public appearance at the world cup soccer finals. Tremendous emotion for that man. Reporter today workers erected the stage where hell be memorialized tomorrow, as police began erecting a perimeter as part of a security undertaking as big as any country has faced. Protecting up to 100 heads of state and government ministers who continue to fly in today along with 95,000 members of the public. Any collection of such dignitaries provides a real risk and a potential platform for terrorist organizations. In that sense, the South Africans have to be ready. Reporter president obama left washington today for south africa accompanied by george and laura bush and hillary clinton. President s clinton and carter traveled separately. Also converging on south africa, leaders from four continents, from britains David Cameron and braz brazils dilma rousseff. And cubas raul castro. The leaders will be behind bullet proof cast. The white house has confidence in the security arrangements including cancelling military leaves. Youve got all the police, Army Deployed at the moment working together with the american and other secret services around the world. Reporter today the official program for the memorial was released listing family, friends, and foreign dignitaries including president obama as speakers. But while its a reminder the world embraced south africa, it is South Africans who claim him. We with wouldnt miss it for the world. Reporter Martin Yonkers and his wife are among the perhaps tens of thousands who will try to attend tomorrows memorial. Their gratitude to mandela rooted in an interracial relationship that would have been illegal under apartheid. We never could have been together with all my friends if it wasnt for mandela. Reporter president obama arriving here early tuesday morning. Were told hes been working on his speech, but, brian, no preview of exactly what he plans to say. Lester holt in soweto tonight. Lester, thanks. As we said at the top of the broadcast as lester repeated, four american president s will be here to honor and remember Nelson Mandela. That has only happened once before when four president s traveled to jordan after the death of king hussein back in 1999. Former president carter was the first to arrive here. And earlier today i had a chance to sit down with him in johannesburg as he recalled meeting his friend Nelson Mandela for the first time. I had a chance to meet with him and winnie. He reminded us that our daughter ai my had been arrested three times as a College Student for demonstrating against apartheid. Obviously that formed an instant friendship. Reporter do you have any concerns about a postNelson Mandela south africa, even though he was out of a policymaking role, as you know, his presence, his aura made for an era here. I dont think there is any doubt that since nelson left office the harmony between black and white people here has gone down. And nelson was dealing with it in a very inspirational way, appealing both to black and white people here on an equal basis. Im not sure his successors have been able to do it. Reporter what is it about the sadness . We knew this day would come. He was a 95yearold man. And yet the signage on the streets thanking him. Theres a sign asking, how did he change your world . It seems so sad here to have him gone. It is. You know, ive been impressed with the South African attitude toward nelsons death. One is as you just mentioned sadness. The other is celebration. You know, theyre happy, bright, vigorous people on the streets singing songs of joy about what his life meant. Reporter president clinton has described him as almost on par with ghandi. Others have said he joins gandhi and king as some of the major figures of the last hundred years. Where do you put him . I think so. I would say that ghandi and Martin Luther king jr. And Nelson Mandela would be in the forefront along with mother theresa as though people you look on with a great deal of admiration and also inspiration. And i think nelson will go down in history as one of the leading people of the century. Former president jimmy carter here in south africa today remembering his true and dear friend Nelson Mandela. We are joined here in south africa by nbc news special correspondent charlayne huntergault, a longtime responsibility who has lived here for 16 years now. And youve come to know the Mandela Family well. What do you hear tonight . You know, i think that they like the rest of south africa had their moments of sadness. And now theyre celebrating his life. They are i spoke with venzi mandela a few moments ago, and she wanted the world to know that first of all, she took out solar lanterns to the children. You saw pictures of the children earlier. She wanted them to have this light to the remember that her father loved children. She said she wanted the world to embrace one word. Forgiveness. I thought that was interesting. You know, she was the one who, i think around 22 years old when mandela was in prison and wanted to get a message to his followers to keep going and keep the struggle going, and winnie was banned, the mother, and so she was the one that read the speech. So i think its great shes now telling the world what she thinks her father would want them to remember. Im impressed at the signage and iconography in public. Thank you, tata, thank you, madiba. Its very paternal as we discuss the day of his death. Exactly. It didnt shock me but in a way pleased me. I was in soweto the other day. While the majority as in the country of the people who were there were black, many white people were there. Calm, comfortable. They brought their children. They talked about how important it was for their children to be there. And so in spite of the difficulties in the country, i think some things are progressing. Well take it as a legacy. Well see you tomorrow as part of our coverage. Indeed. A note about the live nbc coverage of the memorial events honoring Nelson Mandela, early tomorrow morning, 4 00 a. M. Eastern time to be exact. Well be in soweto as leaders from around the world pay tribute at a National Memorial service. President obama, of course, leading the u. S. Delegation. Now we transition from here to the big story back home. Tonight the National Weather service says 48 million americans are living in areas under a Winter Weather advisory of some sort. All of it related to this big and sprawling and really relentless winter storm system that ultimately stretched out from texas in the west all the way north to maine knocking out power and causing a mess on roads and at airports. It sure did make for interesting nfl games yesterday. Nbcs tom costello is in icy cold washington, d. C. , for us this evening. Tom, good evening. Reporter hi, brian. Weve had 24 hours of ice and snow. Many schools are out. And now were bracing for round two. More snow. Oh reporter from falling slabs of ice, even in plano, texas, to an absolute whiteout on i94 in wisconsin and a deadly 30car accident. I looked up and just swerved dodging cars and we ended up in the ditch. Reporter across a huge section of the country, cold ice and snow have got a vice grip on millions of people. More Chain Reaction crashes on the pennsylvania turnpike involving 40 vehicles. One man was killed when he got out of his car. When on the field hes got it. Reporter blizzard football for the eagles lions game. Philadelphia buried in eight and a half inches of snow. On the steps made famous by rocky balboa, half a dozen atvs did donuts in the snow. No, its not legal. Further south, d. C. And the suburbs have been caked in ice. Cars, roads, tree limbs and power lines covered in it. Snapping tree branches and cutting power to nearly 100,000. Among them the ratigans who at least have a fire to keep them warm. The power goes out here more often here than in any country we have ever lived in. Reporter its now a race against time with with rain and sleet falling. The power crews are anxious to get lines repaired before d. C. Is hit with with up to five inches of snow. In dallas so much ice that on the highways today, they were down to a crawl. The snow and ice extended west into colorado and utah. Meanwhile, delays and cancellations at the nations airports. Flight awares misery map showing where tens of thousands of passengers are most affected. On united flight 5311 today milwaukee to chicago, the deicing delay lasted three hours. Flight aware. Com reports 1700 Flight Cancellations so far. That number is growing and the snow is going to arrive just in time for the morning rush hour. Brian . Oh, boy. A lot of trouble there. Tom costello, washington, d. C. For us tonight. Tom, thanks. For more on where this seemingly endless storm system is headed over the next 24 to 48 hours, lets go to Weather Channel meteorologist mike seidel. Hes in leesburg, virginia, tonight. Hey, mike. Reporter hey, brian. Good evening. At least today temperatures crept above freezing for a few hours allowing some of the snow and ice to melt. That will end quickly tonight. Another storm blows into town just before sunrise. A serious impact on rush hour. More snow. Lets take a look. Three to five more inches. Baltimore, d. C. , philadelphia. Philadelphia had more snow yesterday than they had all of last winter. Then its the cold air, reinforced frigid air in the upper midwest. Minneapolis st. Paul with a wind chill at lunchtime at 20 below zero topping out with temperatures being 30 degrees below average. Then thursday, the coldest day here in the northeast. Highs stuck in the 20s. And, yes, more problems at the big city airports in the northeast. Flights have already been canceled, brian. Expect long delays. And i dont like seeing that fog in leesburg either. Mike seidel, thanks for being with us tonight. Still ahead for us tonight, theres something in the cancer fight making health news. Its offering stunning results for some. And later more from here in south africa including our conversation with bono about his friend of so many years, Nelson Mandela. We mentioned health news tonight specifically in the fight against cancer. A small but significant study this time involving patients suffering from the most common forms of leukemia. They were all told that the conventional treatments like chemo were no longer working. They were all given one last hope by doctors. This story is about what happened next. Our report tonight from our chief medical editor dr. Nancy snyderman. Reporter less than a year ago bob levis was relying on blood transfusions to stay alive. He had aggressive leukemia and was quickly losing hope. I met with my lawyer, updated the will. Because i thought it was headed that direction. I didnt see a lot of options out there. Reporter so he signed up for an experimental treatment at the university of pennsylvania. Doctors there genetically engineered his white blood cells and transfused them back into his own body to fight and destroy the cancer cells. I think this is really a new paradigm in cancer treatment. This is really using a patients own immune cells to treat their own cancer. Reporter the study started small in 2010. But early outcomes were so promising, researchers enrolled more adults and children. Experts say the results released this weekend are remarkable. 59 patients with the most common forms of leukemia were treated in the study. Many had significant improvement. And today, 25 are cancer free. Including 8yearold emily whitehead. In 2012 she was within days of complete organ failure when she got this new treatment called targeted cellular therapy. The shortterm sidesques can be miserable. Most patients have severe flulike symptoms like emily did. But her parents say it was worth it. Emily is doing amazing. She is in 3rd grade. She was able to keep up with her class. Shes really just a normal child right now. Reporter doctors say proving this is a cure will require following these patients and others for years. Most agree the approach is the new frontier in fighting leukemia and other cancers. Im in complete remission. And thats a good place to be after being on deaths doorstep just a few months ago. Reporter for bob and his family, its the gift of life. During a Holiday Season he thought he would never see. Dr. Nancy snyderman, nbc news, new york. And were back in just a moment with the new additions to the shrine of the greatest of all time. Tonight the federal government has sold its last remaining shares of general motors, nearly five years after the Emergency Rescue of the American Auto industry when the bottom fell out of the economy and gm received almost 50 billion, an influx in cash to stay afloat. In total american taxpayers lost about 10 billion on the bailout. Tonight its official. American airlines and u. S. Airways have completed their merger. And the new airline is now the largest in the world leaving just four carriers controlling more than 80 of the air travel market in the u. S. A situation some fear will lead to higher ticket prices ultimately. The newest inductees in the Baseball Hall of fame are baseballs winningest managers over the past four decades. Joe tory, tony larusa and bobby cox, all unanimously elected. The induction ceremony next july in cooperstown, new york. Before he left for south south africa, president obama was at the Kennedy Center honors last night in washington. This year, billy joel, shirley mclean, her by hancock, Carlos Santana and martina oroyo. When we come back, more on the life and times of Nelson Mandela. And a tribute from an icon in the music world who was a longtime friend and fellow activist. Back here in south africa. Its now close to 2 00 in the morning local time. Most of the crowds have dispersed for the night, and most of the nights lately its been raining. This is the growing memorial outside the Mandela Family in the upscale houghton neighborhood just outside johannesburg. Ever since word arrived late thursday that mandela had died, his friends and admirers have around the world have been streaming in here to say goodbye. Some prominent, some not. They have filled all the available flights here. One of our colleagues today spotted president carter on his flight. We spotted bono on the flight we were on. Once on the ground in johannesburg, we asked the longtime u2 musician and veteran activist to talk about his friend of so many years, Nelson Mandela. When i get sad about the loss of a friend and mentor and a guide, i just think, here is a chance for us to reboot the whole thing again and go after these ideas. Theres a speech he gave in Trafalgar Square in 2005 as long as poverty, injustice, and class inequality persist in our world, none of us can truly rest. These words basically were, you know, instructions for me. The idea of not thinking about poverty and the fight against poverty, i knew it. But when he said it, you know, it just made it clearer. The man whos made famous with that salute, you know, the fist. The fist opening into a shand shake. You know, this man with all the reasons in the world to hate his enemy. But he refused to hate because not because he didnt feel rage, but i think he just thought love would do a better job. We were asked to write a song for the film mandela which is an extraordinary film. Its an extraordinary honor. If you havent noticed, were not african and its kind of south africa at the heart of it. It goes kwb the sea wants to kiss the golden shore. The sunlight wants your skin. All the beauty thats been lost before wants to find us again i cant fight you anymore. Its you im fighting for. You im fighting for he called me a friend. You know, i was really a fan. Thats probably a fair description. We spent lots of time together, im pleased to say. He didnt belong just to south africa. He belonged to the entire continent. He didnt just belong to the entire continent. He belonged to the world. One of Nelson Mandelas many friends whove arrived here to say goodbye starting tomorrow. That is our broadcast for this monday night. Thank you for being here with us. Im Brian Williams reporting from pretoria, south africa. One more reminder. Were back on the air providing live coverage starting tomorrow at 4 00 a. M. Eastern time. The Memorial Service for mandela. Coverage will then continue on today. We will, of course, look for you right back here tomorrow evening. For now, good night from south africa. Thanks for joining us. Im janelle wang in for raj mathai. Im jessica aguirre. Our top story, the cold snap. Were moving into our sixth straight night of cold weather in the bay area. Again, a freeze warning is going out. This is record cold. Could be linked to another death, the sixth in the past week. We have Team Coverage on the weather, looking live downtown san jose. Cold Weather Triggering another air quality alert, spare the air day called out not only for today but tomorrow as well. Third consecutive spare the rare day tomorrow. Live look at sfo, where passengers have been stranded because of the Winter Weather across the country. We begin tonight with chief meteorologist jeff rainier i, tracking the cold. Were certainly have numbers that have been rivaling that off and on throughout the last four, five days. Average low, 36 degrees this time of year. 15 degrees colder than we should be setting off a widespread record. Freeze warning in effect tonight through tomorrow morning with the worst cold up into the north bay. For napa, marin, also sonoma counties will temperatures will easily range from 21 to 36 degrees. The most critical thing right now is to know that by 10 00 p. M. Tonight, temperatures will likely be in the 20s in napa, also santa rosa, down to 27. Livermore, 36 and san jose expecting 38. Now, this cold weather thats started off way back last week here helped to develop this