trying to raise the wall it keep it out. sad to see it go. >> thanks for joining us at 6:00. lester holt joins us left for "nightly news." >> hope to see you back at 6:00. good night. night, nuclear deal. a historic agreement with iran. tonight, what's in it and what it means for iran's ability to make a nuclear weapon. campus massacre. at least 147 killed, scores injured as terrorists unleash a horrifying attack. shocking searches found in the co-pilot's computer. what investigators say he was looking for in the days before crashing that plane. nbc news exclusive, the father of american sniper chris kyle speaking for the first time since facing his son's killer at trial. tonight, why he feared more for his son at home than at war. and, that's a wrap. our cameras among the last ever on the set of "mad men." "nightly news" begins right now. from nbc news world headquarters in

new york, this is "nbc nightly news." reporting tonight, lester holt. good evening. few things have rattled the world quite like the prospect of iran developing a nuclear weapon, which is why all eyes this week have been glued on a small city in switzerland where today nearly round-the-clock negotiations with iran and how to curb its nuclear program finally produced the framework of a deal. one that president obama quickly proclaimed would ensure iran will never be able to develop the bomb. but then there's the issue of what iran gets in return and whether any deal will hold. our team has it covered. we begin with andrea mitchell in lausanne. andrea. >> reporter: good evening, lester. it's been 18 months of tough negotiations ending with an all-nighter that still left several key issues unresolved. but tonight the united states could be entering a new era in its relationship with iran. and president obama is telling critics this will make our world safer. after marathon talks that almost broke

down, an agreement far more specific than many had expected. the weary negotiators set off to sell it back home as president obama launched what will be a tough campaign. >> if iran cheats, the world will know it. if we see something suspicious, we will inspect it. iran's past efforts to weaponize its program will be addressed. >> reporter: it requires iran not to enrich uranium to weapons grade for 15 years. to reduce its number of operating nuclear centrifuges from 19,000 to just over 5,000. to increase the time it would take to make a bomb from a few months to a year. and to convert its underground plutonium reactor to peaceful research. u.n. inspectors will have full access to all of iran's nuclear facilities. and iran gets relief from sanctions only if it meets its commitments. iran's foreign minister javad zarif claimed victory on sanctions. >> when we complete our measures, there

will be no sanctions against the islamic republic of iran. >> reporter: they couldn't agree on when they would be lifted. and zarif immediately rejected a state department fact sheet tweeting, there is no need to spin using fact sheets so early on. zarif and kerry also couldn't agree on a joint statement. if you couldn't agree on standing up together and announcing together exactly what you've agreed on here, what makes you think that in the next three months you're going to actually come to an agreement? >> because there's a great deal of difference for them between what happens now and where this goes and what can happen when you have a final signature. >> reporter: you think you can get a deal by june? >> i'm not promising anything. nor is the president. what we've done is open up the opportunity. >> reporter: but first they'll have to persuade congress and iran's skeptical neighbors. andrea mitchell, nbc news, lausanne. >> reporter: this is ann curry. the u.s. and iran are trumpeting today's deal, but others are deeply skeptical. israel called it a historic mistake. prime minister

netanyahu tweeting, any deal must significantly roll back iran's nuclear capabilities and stop its terrorism and aggression. and israel has surprising company. much of the arab world agrees iran with its regional and nuclear ambitions cannot be trusted. that includes another u.s. ally, saudi arabia. >> everybody wants a good deal that prevents iran from developing an atomic bomb. >> reporter: but the agreement was welcomed by many in iran. desperate to get out from under years of crippling economic sanctions. nbc's ali erusy in tehran. >> when the news of the deal reached tehran, some people took to their cars and went to the main squares in the city honking their horns and flashing v signs celebrating the news. >> reporter: iran's foreign minister speaking this evening after days of marathon negotiations fought again to reassure skeptics that iran's nuclear ambitions are strictly peaceful. >> we have decided to take steps for a period of time to

assure anybody who had concern our program is exclusively peaceful, has always been and will always remain exclusively peaceful. >> reporter: and iran's foreign minister and his team are expected to be greeted with a hero's welcome when they return home tomorrow, lester. >> ann curry tonight. thank you, ann. another major story we're covering tonight, a massacre on a college campus in kenya. terrorists launched a horrifying attack that went on for hours. when it was over at least 147 people were dead, many injured. and a warning, some of these images are, frankly, quite hard to watch. our chief foreign correspondent richard engel has our report. >> reporter: the attack began before dawn. witnesses say masked gunmen entered the campus through the dormitory. students awoke to gunfire. most of the injured were students. so were the dead. survivors say the attackers separated christians from muslims. christians were shot, muslims freed. a student says he escaped by jumping out

a window but hundreds of others were still trapped inside. >> for hours we could hear gunshots and explosions. >> reporter: garissa university college is in the northeast of kenya not far from the border with somalia. it took two hours for kenyan reinforcements to arrive. u.s. counterterrorism officials tell nbc news that once the kenyans did arrive, they were decisive, moving in and fighting. kenya's president took to the air waves to try to calm his nation. >> we continue to pray for a quick recovery of the injured. >> reporter: the somalia-based terror group al shabaab claimed responsibility almost immediately. the militant group carried out a very similar attack on a kenyan shopping mall in 2013. then, like today, with four gunmen. >> you have now competing terror groups in the world, so they have to show that they're relevant and they have to attack on a larger scale. >> reporter: the

kenyan government accused this man, mohamed kuno, also known by other names. leader of elite al shabaab unit. this may be the deadliest attack on a university ever. and it appears to have been long-planned. over a week ago another kenyan university warned its students that al shabaab was plotting an attack. officials just didn't know where. lester. >> richard engel, thanks. a lot of fast moving developments tonight in the investigation into the co-pilot who officials say may have deliberately crashed that plane into the side of a mountain. disturbing internet searches found on his tablet computer as recovery crews discover the second black box at the crash scene. nbc's katy tur with that report. >> reporter: today, in the french alps among the scattered debris recovery workers say they've collected 40 smashed cell phones, larger pieces of wreckage and, finally, in a ravine the normally orange flight data recorder looking so badly burned it was black. still investigators

say they are hopeful the data remains intact. inside the germanwings flight 9525 second black box french investigators hope to learn what co-pilot andreas lubitz was doing when he was alone in the cockpit. and whether just before the plane began its steep descent the autopilot had been manually changed from 38,000 feet to 100 feet as the tracking site flightradar24.com suggested last week. meanwhile, inside lubitz's dusseldorf apartment, german investigators hope to learn more about who he was and why he would allegedly crash the plane. and today they released some of what they found on lubitz's tablet computer. the user name, the personal correspondence and the entered search words carry the conclusion that the device was used by the co-pilot, said the prosecutor. from march 16 to march 23, the week leading up to the crash, he says lubitz studied

medical treatments, various ways and possible methods of committing suicide and that he spent several minutes on cockpit doors and their security measures. german officials say they're going to look into cockpit security measures to see if they went a little too far after 9/11. they're also going to look into medical and psychological testing requirements for pilots to see where they can improve. katy tur, nbc news, germany. here in new york two women are under arrest accused of conspiring to commit a terrorist attack in the u.s. investigators believe they were inspired in part by isis. the feds say one of them had propane tanks and instructions to turn them into bombs. but one official adds there was no specific plot. under mounting pressure, lawmakers in both indiana and arkansas move late today to change their state's religious freedom laws, which critics have labeled anti-gay. nbc's gabe gutierrez explains. >> reporter: today, indiana republican lawmakers announced an unlikely compromise.

>> religious rights and individual rights can co-exist in harmony together. >> reporter: the agreement follows intense national backlash when indiana passed a religious freedom law. the new language spells out the law does not authorize a provider to refuse to offer or provide services on the basis of sexual orientation or gender identity. why wasn't this language included in the first place? >> well, honestly, the language wasn't needed to clarify the statute legally. it is needed to clarify, the perception of it. and we fixed it. >> did you misinterpret the bill? >> absolutely not. >> reporter: lobbyist eric miller. one of the original law's backers remains defiant. >> you're going to jeopardize the freedom for a christian businessman or another faith to be forced into doing something against their religious beliefs. >> reporter: late today arkansas'

governor signed a revised version of that state's religious freedom bill. >> this bill is bipartisan. it has received overwhelming support in both houses. it protects religious freedom. >> reporter: so did indiana's governor as the spotlight shifts to this weekend's final four. gabe gutierrez, nbc news, indianapolis. in february as movie goers were still flocking to see "american sniper" in theaters, the parents of the real chris kyle were in a texas courtroom watching the man who killed their son stand trial. now for the first time since the trial kyle's father is speaking out. i sat down with wayne kyle to talk about all that's happened. how are you and debbie doing? i mean, there's this movie and there's this book and all this, but we're talking about your son. how are you guys doing? >> surviving. it's been the toughest two-plus years of our life. >> reporter: what was it like to sit in the courtroom with him?

>> it was horrible. i mean, gut wrenching. it's just one of those deals that you just want to jump over that railing and kill him with your bare hands. >> reporter: chris kyle left the navy in 2009. when we spoke three years ago, he told me he found purpose in helping other struggling vets. >> i want to try to figure out everything i can do possibly to help those guys. >> reporter: wayne kyle worried about his son. >> lester, i told him one time, i said, son, i worry more about you as a civilian than when you were with the teams. he said why is that. i said because you were fully trained, highly skilled in what you did. but i said there's no training to be a civilian. >> reporter: in 2013 kyle and his close friend chad littlefield were murdered on a texas gun range by eddie ray routh, a struggling vet they were trying to help.

>> we the jury find the defendant, eddie ray routh, guilty. >> reporter: it was the "american sniper" trial. >> that was so, so wrong. i don't know how every branch of the media portrayed it. >> reporter: i said the words. i bought into it. it was the "american sniper" trial. >> we resent that because it was just then about the loss of chris. the loss of chris was no more of a tragedy than loss of chad littlefield. >> reporter: on the heels of the film's success and the trial, a texas congressman introduced a bill to posthumously honor kyle the medal of honor. >> if you knew chris, you would know he would never ever want that. he never saw himself as a hero. >> reporter: the kyles honor their son through a foundation that supports veterans causes.

they are moved by the tributes of strangers for their son and are happy to have the trial behind them. >> we never had any peace to try to grieve, i guess, ourselves. but once they came back with that guilty verdict, it was like, okay, that chapter is closed, and there was a sense of relief. >> in february the man who killed kyle and chad littlefield was sentenced to life in prison without parole. still ahead for us here tonight, the loss of a legendary figure on television. also, tornado and severe thunderstorm warnings. the threat across a huge part of the country again. al roker will join us in a moment. and later, saying good-bye to the '60s. we're on set among the last cameras there with the cast and creator of "mad men."

once again tonight a huge part of the country is on alert under threat of severe weather. we've already seen a tornado warning. al roker is in the studio with us. are we looking at a long night here? >> we certainly are, lester. on into tomorrow. this is an area that stretches all the way from pittsburgh into nashville. the storms are really just starting to get warmed up. we're watching this activity push on through. and as it does we're going to watch these systems push in and start to fire up. we expect to see strong storms. we already have a severe thunderstorm watch out from jackson all the way to nashville. we're watching that. ahead of this system

we've got warm, moist air pushing in. and then behind it we've got colder air. and between those two that's where we're looking at the strong storms for tonight. we also expect to see heavy thunderstorms firing up. the enhanced risk stretching from springfield all the way to paducah overnight on into tomorrow it makes its way from nashville, jackson on into parts of the appalachians. heavy rain will be falling, lester. we have flash flood watches in effect. some areas picking up 3 to 5 inches of rain before it's all over. >> all right, al. thanks. we'll see you in the morning. the worst rainfall in decades has created epic flooding in chile sweeping away cars, trucks, buildings, even some entire towns right off the map. at least 24 people are reported dead, dozens of others missing. we're back in a moment to remember a man who millions tuned to every week for decades.

the reverend robert schuller has died. the famed televangelist from

southern california who built a megachurch known around the world. he passed away at age 88 after a battle with cancer. here's nbc's miguel almaguer. >> let us rejoice and be glad. >> reporter: from his california pulpit a global audience of 30 million. >> good morning. >> reporter: the reverend robert h. schuller was best known for the "hour of power," that influenced the generation of megachurch pastors. presidents came to worship, but it didn't start that way. when he was 4, guidance from his uncle. >> he put his hand on my head and said, robert, you're going to be a preacher when you grow up. and i said, oh, really? and i added it to my little prayer at night. >> reporter: in the 1950s he preached at a drive-in from the roof of a snack bar. >> this is the day that god has made. >> reporter: in the '80s his congregation grew. the $20 million crystal cathedral was the beacon of his popularity, but by the new century his ministry unraveled. the church filed for

bankruptcy. >> life's not fair. >> reporter: diagnosed with cancer two years ago, tonight reverend schuller is remembered for his message. >> if you can dream it, you can do it. >> reporter: miguel almaguer, nbc news, los angeles. when we come back after the break, we were one of the last to visit the iconic set of "mad men." what we got to see before it signs off.

it's the end of an era for a show that chronicles the end of an era. the final seven episodes of "mad men," the emmy-winning series that revolves around a 1960s advertising agency ends this sunday. we were among the last to visit the set before it wrapped up for production. nbc's kate snow caught up with the cast and creator for one last trip back in time. >> reporter: it was the first of its kind for basic cable. a show that created a sensation and drew rave reviews from the very first episode. >> who are you? >> i'm peggy olson, the new girl. >> welcome to the rainbow room. >> thank you for having me here. >> reporter: creator matthew weiner wrote the pilot 14 years ago. >> i sold the show at the beginning by saying this is a very sexy period in american history that's kind of been

ignored. >> what you call love was invented by guys like me to sell nylons. >> is that right? >> reporter: winer introduced viewers to the glossy world of a new york city ad agency. >> i heard right away from people a really strong identification with a lot of the characters no matter how flawed they were. >> reporter: jon hamm was an un known when the show began. seven seasons took his character don draper from 1960 to 1969. >> armstrong is on the moon. >> reporter: fans obsessed over the show's meticulous detail from the tchotchkes on her dresser to the period stove in pete campbell's kitchen. and the lady bug wallpaper. we got to visit the set before shooting wrapped. >> if you opened up any of these folders, there's actual expense reports. >> reporter: for the actors nearing the end of a show that launched their careers is bittersweet. >> i know that i will see these people again, but i will never see peggy again. and i will never see don again. and i will never see joan and i will never

see pete. and that to me is the sad part. that's what gets me. >> reporter: they bonded between scenes in this oasis they called base camp. we got a rare peek. >> people are texting you got to come down we're playing catch phrase right now. >> i never had that on a show ever. where people want to just hang out. >> reporter: why do you think "mad men" has done for television? >> that's for other people to say. that is really for other people to say. i hope it's had an affect on tv in the sense that it doesn't have any guns and it's a pretty small story and we managed to squeeze 92 hours of drama out of something that is pretty much, i mean, don's life is more exciting than yours and mine, but pretty much derived from real life. >> way. >> yes. >> reporter: he knew how the series would end for about four years, but in true "mad men" fashion nobody's revealing secrets. >> it's an important part of the story, the end, and it will, i hope, affect the audience just as much as it affects us. and they'll miss it as

much as we miss it. >> reporter: kate snow, nbc news, new york. >> and that will do it for us on this thursday night. i'm lester holt. for all of us at nbc news, thank you for watching, and good night. the bay area comes together to honor an officer who gave his thrive protect and serve. >> although we knew it was okay to cry, it was equally okay to laugh. >> a man remembered for his generous heart. >> if yo you were lucky enough to call mike a friend you know mike gave you his all. >> an officer respected for the people he helped. >> i want to give mike a standing ovation for the awesome life that he gave for us. >> tonight team coverage of the memorial for officer michael johnson. good evening and thanks for being with us. i'm raj mathai. >> and i'm janelle wang.

jessica aguirre is off tonight. a final salute for officer michael johnson, the san jose police officer killed last week in the line of duty. officers from around the country gathered outside the s.a.p. center in san jose in formation to salute honor, and pay their respects to the fallen officer. it was a poignant and emotional day. nbc bay area's michelle roberts was there as thousands of people made their way into the memorial service. let's begin with robert handa. he is live at the s.a.p. center with more for us. robert? >> reporter: well janelle, the family and the police department said they wanted to make sure today's ceremony conveyed not only sorrow and respect, but also an appreciation for michael johnson, the man outside the uniform. hundreds of officers from departments all over the state escorted the procession, bringing michael johnson to the s. s.a.p. center. it was gathering of