good evening. from the u.n. to ground zero to madison square garden, it is a big day for pope francis here in new york and we have it all coming up. but first the political shocker that has rattled washington, exposing a deep rift within the republican party. the announcement that one of the most powerful men in the country, house speaker john boehner is calling it quits. he is resigning from congress at the end of next month in the face of a challenge from members of the far right of his party who believe he's gone soft on democrats. and while his exit is eliciting cheers from those on the right, supporters view it as a shrewd and selfless move to spare the government from another government shutdown. kelly o'donnell explains. >> reporter: out the door. john boehner walked this gauntlet today. minutes after he stunned republican colleagues by abruptly announcing his resignation as house speaker, effective october 30th. >> i decided, today is the day i'm going to do this. it is as simple as that. >> reporter: looking relieved and even happy. he has been under pressure from a few dozen angry house conservatives plotting to oust him. charging he caved to democrats too often. >> just all of this stuff i read about in the paper, and -- you know, i really don't want to hurt the institution and i don't want my colleagues hurt. i don't want to -- don't want to put my colleagues through all of this. for what? >> reporter: today the republican adversaries did not gloat. >> the speaker made a very humble and class move today. >> reporter: but grassroots conservatives at a washington conference claimed victory when they heard the news. >> speaker boehner announced he will be resigning. [ cheering and applause ] >> reporter: the resignation frees him politically. advisers say he will prevent a looming shut down next week by working with democrats to fund the government. with money for planned parenthood that conservatives wanted to block over abortion. his exit comes one day after he made history. the devoutly catholic son of an ohio barkeeper tried for 20 years to bring a pope to congress. his trademark tears flowed and the pope's message of politics for the common good moved him. >> the pope put his arm around me and pulls me to him and said please pray for me. wow! who i am to pray for the pope. but i did. >> reporter: boehner leaves with the same motive that brought him here in 1990. >> people throughout this country do want congress to change. >> reporter: now the sudden resignation sets off a scramble for a successor, perhaps majority leader kevin mccarthy. >> are you going to be the next speaker? >> reporter: but will congress function any better with a new speaker. boehner said by turning the page he hopes his party will unite around a new leader but democrats and some republicans i talk to worry things could get even worse. lester. >> kelly o'donnell, thanks. let's get insight into the strife that led up to the announcement and what happens next. we want to bring in our political director, moderator of "meet the press" chuck todd and joe scarborough, a former joe, a former congressman himself, joe, let's farlt with you. what is part two? will they get the replacement they want? >> well one insider, a very powerful insider in congress told me it will be the same problems but a new guy. but john boehner has taken himself out of the fight and out of the fray, he is going to make his successor's job much easier and that successor most likely is going to be kevin mccarthy. he is moving quickly to get support in his direction and most people that i talked to believe it is going to be kevin mccarthy. and ironically, and i've been through this before and chuck was reporting back when we ran newt gingrich out of town and it put the far right on the defensive and made the next speaker's job easier. john boehner was there when we did that to newt. he suspects this will make his successor's job easier as well. >> and chuck, let's step back and look at the environment this is happening in here. we're looking at the political environment of a campaign right now. do they reflect each other? >> they do. look, the same energy that this conservative group in the house was tapping into and was sort of expressing and essentially forced boehner to do what he did is what we're seeing on the campaign trail. in fact we have new nbc news "wall street journal" reports out to show among republican primary voters that we've been testing with presidential race, 72% called themselves dissatisfied with the congressional republican leadership, mitch mcconnell and john boehner. and that is where the fight is playing out. the same energy that's been propelling donald trump, ben carson, and carly fiorina, is the same energy that ousted boehner. so this fight continues on the trail. >> chuck and joe, thanks to both of you. chuck we'll see you for "meet the press." including interviews with hillary clinton and carly fiorina. the fight among house republicans reflecting as we just talked about, what we are seeing in the race for president. the battle of insiders versus outsiders. and today in washington, at a meeting of conservative evangelical groups, the political outsider leading in the polls, donald trump, tried to cut down senator marco rubio. it was another personal attack of an opponent but perhaps not the response trump expected. as katy tur reports. >> speaker boehner announced he will resigning. >> reporter: at the summit in d.c., cheers for speaker boehner's resignation and boos for donald trump. >> you have this clown marco rubio. [ booing ] >> the front-runner not on home turf but trying to court this evangelical and conservative gathering. a crowd which feels let-down by the republican establishment and by slamming marco rubio on immigration. >> he's in favor of immigration and he has been. he has been. it was the gang of eight. and you remember the gang of eight. it was terrible. >> reporter: trump running as the outsider, painting the florida lawmaker as part of the problem. but rubio, a first-term senator who can appeal to the conservative base, didn't back down. >> is he qualified? >> he has to prove it. up until now he has not. >> he's rising in the poll. >> i think he's a baby. he's using me for publicity. >> marco rubio is a popular conservative figure in the republican party and i think you're starting to see at some emotional level the unwinding of donald trump under the pressures of the presidential campaign trail. >> reporter: after months of flying under the radar and refusing to comment on trump, rubio is now attacking. perhaps smelling blood in t water on trump's foreign policy debt. >> donald trump had a bad week. carly embarrassed him on stage and he spoke to an empty room in carolina and he is not reacting well to it. >> reporter: tonight he put his spin on today. >> i didn't get boos, i got cheers. >> he did get a standing ovation when he walked into the room and applause and cheers before and after the booing. but when i asked someone in the crowd if they would vote for him and they laughed and said no, he is not religious or conservative enough. lester. >> katy tur, thank you. here in new york, it was a day filled with emotion and deep symbolism as pope francis touched the lives of tens of thousands. the scene at the madison square garden. the site of the big mass for an audience of 20,000. some 80,000 people crowded streets along central park as the pope traveled downtown for tonight's mass. earlier at the u.n. security council -- at the u.n., he appealed to world leaders to protect the planet and at ground zero remarkable scenes at the september 11th memorial as the pope called on the world to build unity from the circumstances. our report tonight from nbc's anne thompson. >> reporter: the enormity of ground zero dwarfed even pope francis prayed silently at the south pool. the one place in new york the pope insisted on visiting. of the thousand family members on hand, he met with 20. including monica murphy, she showed francis a picture of her first husband michael who died on what she called sacred ground. >> what an honor. he is the closest thing we're going to get to god. >> it was an emotional moment. peter is a retired firefighter. >> it does mean something. it meant a lot. that he came through here. >> reporter: the pope then led an interfaith gathering of the world's religions in t world museum's foundation hall. [ singing ] >> reporter: in front of the wall that held back the hudson river on september 11th, francis prayed for peace. his day began at the united nations. meeting with staff. and delivering a forceful speech about protecting the earth. before 170 world leaders and malala yousef, he insisted that a right of the environment does exist and that man is not authorized to abuse it. the ecological crisis and the large scale destruction of bio diversity can threaten the very existence of the human species. at central park, thousands lined up with tickets to get in, others just hoping for a glimpse. the park became francis' playground with a larger than expected crowd and extra security was ordered. from francis the celebrity to francis the teacher. stopping at our lady queen of angels school in east harlem where children gave him a lesson in touchscreen technology and he gave them a history lesson about martin luther king jr. and the power of dream. and then a homework assignment. please pray for me. and like any good teacher -- >> don't forget the homework. >> a reminder. >> reporter: tonight pope francis celebrates mass at madison square garden and early tomorrow he heads to philadelphia to wrap up his trip. lester. >> and what do you expect the message will be in philadelphia? >> reporter: it is going to be another one of his favorite subjects, lester, it is all about family. >> anne thompson tonight in new york. thank you. at the white house this evening, president obama is hosting a state dinner honoring the chinese president, xi jinping. the strains between the countries on hold for a few hours. earlier today the two presidents came to an agreement on the big issue of cyber theft. we have more from our white house correspondent kristin welker. >> reporter: an elaborate welcome for the president of china, masking underlying tension between the two largest superpowers. but today a small step forward. president obama and jinping announced a joint agreement. neither the u.s. nor the chinese government will engage in cyber theft of intellectual property. >> this is progress but i have to insist that our work is not yet done. >> reporter: while all powers engage in spying, the u.s. has accused china of stealing trade secrets from u.s. companies. >> about 80% of economic espionage today is conducted by the chinese. >> reporter: and china's record on cyber attacks is extensive. the country accused of breaching the office of personal management last year, stealing the records of 20 million people. other suspected targets, major corporations, newspapers, defense contractors, and even the u.s. postal service. today the president announced he is still skeptical. >> what i said to president xi, and to the american people, the question now is are words followed by actions. >> reporter: mr. obama has pursued a strategy of engagement, not confrontation, meeting with him six times in less formal settings meant to foster candid conversations. critics say the u.s. hasn't been tough enough, allowing china to to expand military presence in disputed waters an carry out human rights violations. all of this casting a shadow over today's progress. >> it is important to have china understand that it is a two-way street. >> reporter: now china has consistently denied being behind any cyber attacks. meanwhile the two leaders will have a chance to build on diplomacy tonight during the state dinner which will be featuring lobster and lamb in a blend of american and chinese cuisine. >> kristin welker, thank you. still ahead, what caused that horrific deadly crash on a bridge in seattle. federal investigators are on the scene trying to answer that. and why this pope has such a universal appeal. we'll hear from some who have made the journey and are feeling the spirit. ntsb investigators are on the scene of the deadly crash yesterday between a charter bus and a duck tour boat on a crowded bridge in seattle. a tragedy that claimed the life of four international college students. dozens were hurt and tonight we are learning more about the terrifying moment of impact. morgan radford reports. >> reporter: a somber campus, mourning the lives of four international students killed when a duck tour boat collided with their charter bus. >> i was just shocked. >> the students came to the united states for college from austria, indonesia and japan and china. >> in the beginning, some of the first responders wouldn't find out who they were because they didn't speak english. that is scary. >> reporter: today the ntsb looks into the investigation. >> we look at all aspects. we enter an investigation of this sort thinking anything is possible. let's see where the trail leads. >> the lanes on the bridge where 9.5 feet wide but the duck boat is 8.4 feet wide. but it swerved five lanes and into oncoming traffic and t-boned the charter bus. local residents have long said this bridge is an accident waiting to happen. >> we shouldn't lose people to make a change that needs to be made. >> reporter: this is the bridge where the accident actually happened. but you can see it is tricky because there are no dividers between the actual lanes. so it feels pretty narrow for the speed and the volume of traffic. mark gordon was on the bridge and narrowly avoided the accident. >> there was so many people and too much pain i could tell what was going on but couldn't wrap my mind around it. >> a flood of people ran to the scene to help and may have saved lives. tonight 19 people are in the hospital as the college community prays and begins to heal. morgan radford, nbc news, seattle. and we're back in a moment with the latest news in black and white. the weather made it a very rough night for folks in south carolina. a tornado touched down early this morning on john's island near charleston. it caused severe damage to a dozen houses and uprooted large trees and left several thousand homes and businesses without power but no injuries were reported. the dalai lama has canceled a visit next month after he was ordered to take time to rest. his secretary said it comes after a routine checkup and no particular health complaints. and more big news from washington today, america's newest giant panda cub has a name. we call him bei bei. the first lady unveiled it during a tour of the national zoo. he turns five weeks old tomorrow and weighs about 3 pounds. when we come back, stories of faith. why so many traveled so far to see the pope. next at 6: volkswagen's emission scandal hits silicon valley. ===take vo=== the new lawsuit raising suspicion about a lab in belmont. we'll take you inside that facility. ===jessica/take vo=== and happening now - how the big ac/dc concert could leave drivers "thunderstruck" in san francisco. ===next close=== next. pope francis tonight celebrating mass at madison square garden in new york city. as we end this historic week, pope francis left no doubt that he is truly the people's pope. people have been touched by his handshakes, his smile, his blessings and indeed his mere presence. some waiting many hours to see him after traveling many miles. nbc's miguel almaguer tonight on the experience. >> reporter: they planned for months. they waited for hours, all for an experience that passes in only a moment. >> it was a great feeling. it was fantastic. he's a good man to put down his window and let us see him. >> reporter: love for the pope is universal. crossing cultures and continents. >> i feel so blessed. god bless america. >> reporter: for catholics he is many consider him the closest man to god on earth.many consider him the closest man to god on earth. [ cheering and applause ] >> reporter: they've celebrated their 50th anniversary with the man that embodies commitment. >> it is different. >> reporter: this 12-year-old is a survivor, beating brain cancer. now he is determined to meet the pope. >> i would like to see him in person, shake his hand. it would be cool to do that. >> cool is one way to put it. tonight, no matter the language, the sent meant is the same. migel almaguer, nbc news. that will do it for us this friday night. i am lester holt. for all of us at nbc news, thank you for watching and good night. emissions tests. now a new lawsuit, filed in the bay area, is raising new suspicions about the possible link wv accused of cheating on emissions tests. there's suspicions about the possible link the a local technology lab. tonight we take you inside that lo lab. >> made in germany but perhaps altered here in bay area. they've admitted to installing devices in as many as 11 cars to cheat those tests. a new class action lawsuit points the finger at this research lab on the peninsula right in belmont. we broke the story today and we take an inside look at the facility. we have multiple reports. robert, this scandal hitting home. >> reporter: that's right. this bay area lawsuit is the latest. it's not going to be the last and be people involved say trust will be hard thing to regain. the anger from the late e class action hover over volkswagen's reputation. the two stanford professors who filed the suit are pasat buyers who bought the claims of meeting emission standards. >> they were angry. they feel betrayed because they spent a lot of time trying to figure out what car to get. >> reporter: volkswagen admitted it installed so called defeat devices that