Nightly news, reporting tonight, Kristen Welker. We begin with a potential danger in the sky averted this weekend. Two United Airline pie the lots arrested saturday morning on suspicion of being under the influence of alcohol. They were scheduled to fly 141 passengers from scotland to new jersey. Its not the first time this year pilots have been taken into custody for alleged intoxication. In this case, aviation experts say the system worked, but some passengers on that flight were left shaken and frustrated. Morgan rath ford has our report tonight. Reporter Authorities Say the two pilots are 35 and 45. Their identities still not confirmed. They were supposed to be flying united flight 162 scheduled to leave scotland at 9 00 a. M. Yesterday with 150 people on board. But then confusion. One passenger tweeting, what is going on . Police in the tunnel. Very little information. It turns out the suspected of being drunk. If you are uncomfortable with a member of your crew, you dont fly with them. The safeguards in place did, in fact, work. The entire crew was replaced and the flight was delayed ten hours. Finally landing all the 8 45 last night. Today other passengers there voiced concerns. Pie the los on a plane drunk absolutely concerns me. The two pilots have been removed from service and their flying duties. We are cooperating with the authorities and will conduct our own investigation as well. This isnt the first time this happened. A flight to philadelphia cancelled and a local pilot charged. In march American Airlines pilot failed two breathalyzer tests before takeoff and was arrested. He pled no contest and was put on probation. Dennis murphy flew 151 passengers from orlando to new york while allegedly under reminder of the great responsibility pilots have after an engine problem forced a southwest flight to make an Emergency Landing in florida. Passengers praised the pilot. Were grateful we were watched over and we had good pilots. As for the two pilots arrested this weekend, they are being held at a Police Station in scotland. A long flight for those passengers finally arriving here in newark. Those pilots are Court Tomorrow morning. Kristen . Morgan, thank you for that report. In louisiana now tragedy for a group of workers headed to flood ravaged baton rouge. Two people were killed and more than 40 jurd when their charter bus crashed into several vehicles. Police say the bus driver does not have a license and admitted hes an undocumented immigrant. And now to politics and questions issue deporting undocumented immigrants. Also tonight were getting a look at the stark differences in how trump and Hillary Clinton are prepare ing for their very first debate. We have two reports tonight beginning with jacob rascon in iowa. Whats the latest there . Reporter the Trump Campaign working overtime to calm neshs. Some worried trump seems undecided on a key component of his immigration policy just 71 the election. Donald trump off the trail, but his campaign busy today contending he hasnt budged on his signature issue. What he said is signature. Hes been consistent. His position and principles have been absolutely consistent. After repeatedly declaring during the primaries this every last undocumented inl grant must be deported. They have to go. What if they have we will work with them. Trump singling out criminals, a fraction of the 11 million undocumented immigrants. On day one, im going to begin swiftly removing criminal ul legal immigrants from this country. But what would a President Trump do about the rest . The Deportation Force i would like to address this. He hasnt mentioned that since last november. The softening is more approach than policy. The softening troubling to trump su others. I think there will be a happy medium. The campaign challenged on minority outreach including his i told you so response to the shooting of dwyane wades cousin. Donald trump has a plain spoken way about him. His Campaign Manager asked how many times has trump spoken directly to minority audiences. Would you be surprised if the answer is never . I would not be the Trump Campaign ready to shift the focus back on Hillary Clinton. Jacob rascon, nbc news, des moines, iowa. This is Kelly Odonnell in washington. Four weeks, two very different playbooks. Our leaders have stupid. Our politicians are stupid. Heading into the ultimate debate stage oneonone. I was the first one to call him out. I called him out when he was calling mexicans ci did debate prep his way. Hes an unconventional candidate. Hes not going to prepare the way hillary does which is cram her head with these binders. No formal rehearsal, just hashing out ideas. Including former executive roger ails and radio host laura ingram. Trump has resisted traditional mock debate practice and plans to rely more on s hi gut. Hillary clinton is on the fundraising circuit with four events in the hamptons. This weekend celebrity supporters, Ashton Kutcher and jason george helped out Clintons Campaign while barre baa streisand hit send to raise cash. Clinton has been carefully preparing her responses to meet debate time limits. Her advisers call trump a formidable adversary. Its going to be difficult. Youre going to have to prepare for man wellbehaved, modest trump. I doubt well see that. Kind of off the rail trump. Holding fewer Public Events right now as ve raises money, clinton will call on her most famous surrogates, president obama and Joe Biden Campaign without her in the next couple weeks. There are going to be a lot of eyes on those debates. Kelly, thank you. We want to turn now to the tropics where there are coast. Meteorologist raphaelmy ran did is tracking it for us. Were tracking three storms in the atlantic. One a major hurricane. Thats gast tone moving out to see. But depressions 8 and 9 will affect the southeast. This is the one we have been tracking day after day. It finally got better organized today. Winds at 35 miles per hour. Moving over the warm waters of the gulf of mexico likely to strengthen to a this will make landfall some time towards the middle of the week exactly where remains yet to be seen. Very heavy rain in florida over 6 inches possible in southern florida. Our next tropical depression is headed toward the carolinas. Thankfully also looks to curve out to sea. Still needs to be watched closely in north carolina. We will continue to track all of that. Overseas to the ongoing devastation in syria. More than a dozen when bombs fell on a funeral procession this weekend. Efforts to deliver muchneeded food anden medicine are now on hold. Heres matt bradley. Reporter in the besieged city of aleppo, even the dead face the horror of war. Barrel bombs struck mourners paying their respects to victims of a previous bombing. They were greeted with another round of bombing. Its called a double attack. Twin attacks for maximum casualties. Civilians continue to bare the brunt of this war. Observers have died in aleppo alone. More than a quarter of the victims, children. The u. N. Says russia agreed to a ceasefire to let food and medicine into the city. Theres been some progress, a deal between rebels and syrias government ended a siege last week. Thousands of civilians and fighters were able to leave. But at what cost. Here departing evacuees are heckled by government troops. Syrians worry a ceasefire means surrender and loved ones will have died in vein. Matt bradley, nbc news. Devastating indeed. Country, its the question that will be asked at your next appointment. The state made it illegal for counterparts at the university of massachusetts. We graduated from but not making the same pay. After a long battle with her employer and testimony before congress on pay inequality, the single mother was awarded the same salary as her male colleague. Nbc news reached out to the school that said its unable to comment on personnel matters. This month in an effort to close the wage gap the governor of massachusetts signed a pay equity bill into law prohibiting companies from asking their current or past salary history. Its going to be a model used in the rest of the country. Reporter victoria directs the women in policy program at harvard and says the pay gap can last a lifetime. This matters so much because often if people get a lower salary than their skills would have warranted early in their career. You get a snowball effect. When boston attorney was job about her previous salary. They are asking for your salary history. So it almost felt like in some ways i had to justify why i was asking for a certain percentage or increase from what i was making. She says this it may have cost her thousands. Was there ever a point you felt like maybe you were asking for too much . Definitely. There were times i felt like, well, maybe i can take a pay cut. For both satisfaction in knowing the Playing Field is more level. Its exciting to me that folks will have the tools that they need so they dont have to go through this. So its promising. Nasa may be getting closer to a Human Mission to mars. A team of scientists emerged after being kept from the odds world for an entire year. They simulated what life would be like on year of total isolation, today they are returning to civilization. Im super excited because its the first time we get to be outside. Reporter six scientists walked into this 36foot wide solar powered dome last august. Im looking forward to getting to act like an astronaut for a year. On the rugged slope, its the longest ever nasa mission to understand how a yearlong space trip wou a astronauts. Thats the view from simulated mars. Emails with family and friends are on a 20minute delay from mars to earth. Going outside required a full space suit. They conducted experiments on plant growth and water, but the big question today are they still friends . We could definitely use some other time to talk to other people. Plus fresh fruit and a beer, saying goodbye to their home sweet dome. Now that is incredible. Still ahead, stopping the zika virus with mosquitos. The push to use extraordinary starts here. New ky intense. A stimulating gel that takes her pleasure to new heights. Ky intense. Were back with a push to get control of the sooe ka outbreak by the same way its being spread. Were talking about mosquitos. Its an invo native idea approved by the fda, but is it safe . Heres nbcs gabe gutierrez. In the sleepy florida keys, theres a political storm brewing. A fight over government, science i would absolutely feel like a gi any pig. The local Mosquito Control district is looking into a plan to be the first testing ground for e genetically modified mosquitos to stop the spread of diseases. The insects would be released in key haven. They called it ju ras sick science. Whats being objected to is the safety for the environment and the people. Mosquito eggs would be injected with a specific gene. When they mate with e offspring die more quickly reducing the mosquito population. A scientist with a British Company behind the project. We have done trials in brazil where in every single case we have shown over 90 of the control of the mosquito population within six to nine months. Reporter the debate has intensified amidmoupting fears of zika virus. Federal Health Officials issued travel warnings for pregnant women and parts of miamidade home grown zika in the keys, the risks outweigh the benefits. These cannot be recalled. Once they are out there, they are out there. Theres not enough information. They are mounting a campaign. Gabe gutierrez, nbc news, miami. Coming up, we go to a critical swing state, iowa. The key question for politics, the state of iowa could help determine who wins the white house and the number one concern for voters there is jobs. Its an issue thats taken on fresh urgency days after hundreds of positions were cut at one large company. Jacob soboroff talked to voters there. These two buildings are part of the original part of john deere manufacturing. They are over here in the new facilities here. Were down to maybe 3,000 employees. Factory worker at john deere until he became one of many on the Assembly Line let go. 100 people losing their jobs. The company says that workers like robbie get laid off due to the ups and downs of the market. Since then they have shed more than 1,000 jobs. Hansons dairy farm is just outside waterloo. Blair hanson is the sixth generation to tend to these fields. How old is this tractor . I heard they have been laying people off. Corn prices are low. Farmers cant afford to buy new tractors. The plants slow down and they have to lay people off. When it comes to the candidate between clinton and trump, you have a feeling one way or the other who can bring jobs like the has the better chance. Hes a businessman. Hes going to look out for business people. In this county where Bernie Sanders and ted cruz won the iowa caucus, who can bring the deer jobs back . Maybe ill go around on the next round of president s. Im going to say a he. Got to be he. He. She. I dont want either one of them. Id have to go she. Hillary clinton . Yes. Ross perot. Like their fellow iowan, the they have two months left to debate candidate is best for their neighbors. Jacob soboroff, waterloo, iowa. Thats the way to talk about politics. We have a sad note to report from the music world tonight. The mexican singer and died unexpectedly. He performed this weekend to a sold out crowd in california. He sold more than 30 million albums. He was 66 years old. Still ahead, how one little girl is finally tonight in a heated rhetoric, a young girl is doing Something Special to spread a little kindness. Her Humble Movement has gone global. Heres steve patterson. If youre trying to keep up with her, good luck. Heres some bracelets. Because when shes on her mission, few can. Whenever youre kind to someone, you give them the bracelet along with the note. 10 yoerld leah nelsons vision is is simple. I want to live in a world where everyone is nice to each other and everyone can be the best person that they can be. Times, its striking a nerve. Earlier this summer when grown up on the news were showing how ugly they could be to each other, leah came up with something beautiful. Get people to pay it forward with kindness. I said, dad, im going to hand out some bracelets and people will have to be kind. I hear about 30 ideas a week from leah. Its one of those things, okay, ill see how far she takes this. Using an old birthday gift, a bracelet making kid hit, she started making them by the dozens and hit the streets asking people to take one, do something good and then give them the bracelet and ask them to do the same. Thank you so much for everything you do. It all started at Community Events just like this. Leah trying to make a difference in her own backyard, but 20 million views on facebook later and her message of kindness is touching people all over the world. 102 new messages. Requests for the out in person is still her favorite part. Dont eat it. Thank you very much. Leah says shes just being herself. My dad tells me to be me and thats what i try to do. I think thats what im good at. Wisdom from a 10yearold we might all use. It doesnt cost anything. Steve patterson. Nbc news, west sacramento, california. What an inspiration she is. That is nbc nightly news for this sundays. Im Kristen Welker reporting from it new york. Fo for watching and have night, too drunk to fly. Two pilots arrested moments before they were set to take off for the u. S. The latest scare of the busy travel season. The showdown, a month before their first debate, the stark differences in how donald trump and Hillary Clinton are preparing to faceoff. Trouble in the tropics. Gathering storms could put the eastern sea board on alert. To unleash genetically modified mosquitos to control the outbreak. And Mission Accomplished how scientists emerging from a year in isolation get one step closer to a Human Mission to mars. Nightly news begins now. From nbc news World Headquarters in new york, this is nbc nightly news, reporting tonight, potential danger in the sky averted this weekend. Two United Airline pie the lots arrested saturday morning on suspicion of being under the influence of alcohol. They were scheduled to fly 141 passengers from scotland to new jersey. Its not the first time this year pilots have been taken into custody for alleged intoxication. In this case, aviation experts say the system worked, but some passengers on that flight were left shaken and frustrated. Morgan rath ford has our report tonight. Reporter Authorities Say 45. Their identities still not confirmed. They were supposed to be flying united flight 162 scheduled to leave scotland at 9 00 a. M. Yesterday with 150 people on board. But then confusion. One passenger tweeting, what is going on . Police in the tunnel. Very little information. It turns out the pilots were arrested suspected of being drunk. If you are them. The safeguards in place did, in fact, work. The entire crew was replaced and the flight was delayed ten hours. Finally landing all the 8 45 last night. Today other passengers there voiced concerns. Pie the los on a plane drunk absolutely concerns me. The two pilots have been removed from service and their flying duties. We are cooperating with the authorities and will conduct our own well. This isnt the first time this happened. A flight to philadelphia cancelled and a local pilot charged. In march American Airlines pilot failed two breathalyzer tests before takeoff and was arrested. He pled no contest and was put on probation. Dennis murphy flew 151 passengers from orlando to new york while allegedly under the influence. Just yesterday a reminder of the great responsibility pilots have after an engine problem forced a make an Emergency Landing in florida. Passengers praised the pilot. Were grateful we were watched over and we had good pilots. As for the two pilots arrested this weekend, they are being held at a Police Station in scotland. A long flight for those passengers finally arriving here in newark. Those pilots are expected to appear in Court Tomorrow morning. Kristen . Morgan, thank you for that report. In l tragedy for a group of workers headed to flood ravaged baton rouge. Two people were killed and more than 40 jurd when their charter bus crashed into several vehicles. Police say the bus driver does not have a license and admitted hes an undocumented immigrant. And now to politics and questions over Donald TrumpsSignature Campaign issue deporting i got my bag and my ran. A chaotic scene overnight at Los Angeles International airport as loud noises cause panic. And former campaign for president obama calls donald trump a psychopath, this agency the candidates prepare for their debate just 29 days from now. New detailing surrounding the death of dwyane wades cousin. And flash floods in the mississippi area. And the vmas. And the early win for summer