Go go and Serena Williams marching towards history and tennis coveted prize, the epic showdown with her sister on the sports biggest stage. Stars filling the stands as serena moves one step closer to history. We do say good morning, america. Who stayed up to watch the match last night . It went three sets and now Serena Williams just two wins away from becoming the first player since steffi graf in 1988 to win the calendar grand slam and that hug with her sister at the end. Beautiful. It really was. I know, but they are truly each others number one fans. They are. That was so evident. Choked me up. Same way. Yeah. Well see a lot more of it coming up. We will begin with that fiery scene on a runway in las vegas. British airways jet, more than 170 people on board and burst into flames on the tarmac. You see the passengers streaming off the plane and abcs matt gutman on the scene in las vegas. Good morning, matt. Good morning, york. When investigators arrived here later this morning. They took a look to see why the fire spread from the engine to the cargo hold. We got to see the smoke this morning up close. You can see the spokestained fuselage. British airways call it a technical failure but the captain credited with saving 170 lives aboard that plane called it Something Different a catastrophic failure. Speedbird 2276 heavy, we are evacuating on the runway. We have a fire. I repeat, we are evacuating. Reporter this morning the scramble to explain why this jetliner turned into a fireball. Mayday, mayday, speedbird, 2276 request Fire Services. Speedbird, 2276 heavy Fire Services are on the way rfrjts flight 2276 bound for london bursting into flames on the runway in las vegas. You can see them here scrambling to safety. What we had here was an uncontained explosion of a jet engine on takeoff roll and that means it came apart catastrophically creating fire and the necessity for the flight crew to stop the airplane on the runway and get everybody off the airplane. Reporter 157 passengers and 13 crew aboard the 777 starting its takeoff with a belly fuel of fuel. More than a dozen were injured but all of them were in mortal danger. Experts tell abc news a mechanical failure could have caused the engine to come apart spitting out fire and pieces of hot metal which in turn could have sparked a separate fire in the cargo hold. Quick thinking crew helped the passengers flop down the emergency slides to the tarmac. Is everybody okay . We had to jump down. You could see the flames and smoke and thats when it sort of hit me anyway it was pretty scary. Reporter survival instinct kicking in for this mother, escaping with her young daughter. It was so instant, literally it was fight or flight and i just jumped. I couldnt even say i felt anything. Thats how fast it happened. Reporter fire crews sprang to the scene, the plane swallowed in smoke while bystanders, even passengers on other planes, watching in horror. That billowing column of black easily visible from offices a mile away. The fire paralyzing the airport. The airline telling us that all of those injured passengers have been released from the hospital. While it could take some time for this investigation to unfold, what is already clear, is that had that plane taken off on fire, this could have been catastrophic. Robin . Youre right about that. Thank you. Abc news aviation consultant colonel Stephen Ganyard joins us from washington. Give us more details on what happened here, steve. Good morning, robin. Very interesting because what happened is early in this takeoff roll as the airplane ras running down the runway only going 90 miles an hour we say it was an uncontained engine failure. What that means is the engine really just exploded and it sent hot metal into the fuselage and started a fire in the fuselage itself so the fire you see in those pictures is really the airplane itself not the engine thats on fire and after they put the fire out you could see how clearly that fire came to almost penetrating into the cabin which meant this could have been a very serious, serious accident. Oh, absolutely. As matt was saying, as well. You said they put the fire out quickly. They were on the scene like that and the crew and passengers did a great job of getting off that plane so quickly. He did. Apparently what happened is, well, they were right on the middle of the runway so the crews were right there, the rescue crews right there to put the fire out. When the cabin crew opened the door they saw the smoke on the left side of the airplane and so they got everybody out the right side, closed that door back up to keep the smoke out of the cabin. Crew did a great job in this instance but now its going to be up to the ntsb to figure out why did this engine actually blow up. We want answers to that. We all do. All right, steve, thank you so much. Such a strange one. We move to the race for president now. Your voice, your vote and Hillary Clinton finally apologizing for using that private email server. Admitting it was a mistake for the first time in an exclusive interview with abc news, cecilia vega here with that. Good morning. George, good morning to you. She had said she would not apologize for that private email and home server, but now changing her tune with her poll numbers slipping. This is a new contrite Hillary Clinton. That was a mistake. Im sorry about that. I take responsibility. Reporter Hillary Clinton doing exactly what she said she would not do, apologizing for that private email and server not just once but twice. In retrospect certainly as i look back at it now even though it was allowed i should have used two accounts. Everybody in the government, i communicated with, and that was a lot of people knew i was using a personal email. But im sorry that it has, you know, raised all of these questions. I do take responsibility for having made what is clearly not the best decision. Reporter clinton telling abc world news tonight anchor david muir she should have done a better job answering questions. And when voters were asked, what is the first word that comes to mind when you think of Hillary Clinton, words like liar, dishonest, untrustworthy were at the top of the list. Well, david, obviously i dont like hearing that. I am confident by the end of this Campaign People will know they can trust me. Reporter with her poll numbers sliding and her friend joe biden contemplating a run against her would he make a good president . Well, i like joe biden a lot and i think he is a great Vice President , if he gets into this election, there will be lots of time to talk about you know, what he wants to do. Would you make a good president . Well, you know, i think he could be good president , theres no doubt about that. Reporter no doubt either about the woman she misses most, clinton becoming emotional talking about her late mother. And she told me every day, youve got to get up and fight for what you believe in no matter how hard it is. And i think about her a lot. I miss her a lot. I wish she were here with me. Well, there is another headache for Hillary Clinton this morning. Take a look at the latest poll, clinton at 42 there. Her lowest standing. So far this election cycle but its not just that with her numbers slipping, joe biden and Bernie Sanders now rising and this more than half of all clinton supporters say they would consider switching their support to biden if he does jump in the race. George, her supporters hoping that this apology helps turn these numbers around. Can they turn the corner. Okay, cecilia, lets see what happens. Now the latest on that kentucky county clerk jailed for refusing to issue marriage licenses to samesex couples. Kim davis is free this morning. Everyone waiting to see what she does when she returns to work. Abcs alex perez is on the scene for us in morehead, kentucky. Good morning, alex. Reporter hey, good morning, robin. Davis not expected back here in her office until friday or monday. When asked if going to jail was worth it, she smiled and nodded yes. Rising up back on the streets reporter marching out to eye of the Tiger Kim Davis getting a heros welcome from hundreds of her supporters. Davis released after six days behind bars. I just want to give god the glory. His people have rallied and you are a strong people. Reporter davis jailed held in contempt of court for refusing to comply with a judges order to issue samesex couples marriage licenses. Under Whose Authority are you not issuing licenses . Under gods authority. Reporter kim davis refusal to comply putting her own life under the microscope she became a born again christian about four years ago when her motherinlaw died and she says she had a calling to serve god. Before then the 49yearold clerk married four times, twice to the same man. Testifying in court thursday, i did a lot of vial and wicked things in my past. Tuesday, her supporters standing by her side rallied by a tearful gop president ial hopeful, Mike Huckabee. People are tired of the tyranny of judicial action that takes peoples freedoms away. Reporter as a condition of her release the judge issued davis shall not interfere in any way with the efforts of her deputy clerks to issue marriage licenses to all legally eligible couples. But when asked if she would again block her deputies, davis attorneys would only give one answer. Kim davis will not violate her conscience. Reporter and a new legal battle forming this morning, the Rock Group Survivor suing Mike Huckabee for using their song eye of the tiger at that rally. George . We will see what happens with that. Okay, alex, thanks very much. So much of the country baking from this heat wave. Record temperatures in the northeast pushing towards triple digits. The hottest day of the summer. Ginger were in for one more day of this . One more day, and we are stuck under this upper level ridge. Thats whats responsible. The jet stream and the cool air stuck behind it for one more day. We broke records, 97, new york city yesterday. Boston was 96. Hartford was 96. Today not quite as hot. But let me tell you it will be plenty humid and feel just as hot as it was until tomorrow then temperatures will be 10 to 20 degrees cooler as we go toward the end of the week. Where that will not be happening, out west. So Southern California especially from san diego up through the l. A. Valleys there, burbank to 100 with an excessive heat warning. San jose close to 100. And that doesnt end. It goes all of the way to the end of the week and into the weekend. Look at sacramento almost 110. Much more on all of this coming up. All right, ginger, thank you. In the meantime, to the city of phoenix on edge. Police there investigating that series of apparent shootings targeting drivers on the highway. Nine incidents in ten days, abcs Kayna Whitworth is in phoenix for us this morning. Good morning, kayna. Reporter robin, good morning to you. Drivers on this stretch of highway urged to use extreme caution this morning. Authorities saying with no pattern of days or times, everyone is at risk. This morning, arizona drivers on edge while authorities are investigating what they consider a possible act of domestic terrorism. Any time that you have multiple shootings against american citizens on a highway, thats terrorism. Theyre trying to frighten or kill somebody. Reporter officials reporting nine possible shootings incidents over the last ten days, vehicles struck by projectiles as they drove along a short eightmile stretch of i10. The major thoroughfare in the heart of phoenix, arizona. I dont know if its a copycat crime. Reporter the spree, starting august 29th, a bullet, shattering the windshield of this suv, injuring a 13yearold girl. Just minutes later, a shot hit this tour bus, putting holes through the seats. Luckily the driver was the only person on board. The person almost took me away from my family. Reporter and tuesday, two more shootings, one of the cars hit was a Police Sergeants personal vehicle. Both vehicles were hit in the drivers side passenger window by a projectile. I would call that related. Reporter the fbi and atf now joining the investigation, Police Warning drivers to be extra vigilant hoping they can catch the alleged shooter or shooters before its too late. Somebody will get hurt or somebody will get killed if this continues. Reporter so authorities are offering up a 20,000 award for any information leading to an arrest. Also, robin, they put up a type line on these electronic billboards over the highway so people can call if they see anything suspicious. Hopefully that will help. All right, kayna, thanks. Now amy with the other top stories starting with a growing situation over one of the nations biggest airlines. Thats right, robin. The ceo of United Airlines and two others have resigned amid a growing corruption scandal, accused of giving preferential treatment to the former chairman of the new york and new Jersey Port Authority which operates airports in the new york area. At issue is whether united flew a dedicated nonstop route to South Carolina where the chairman had a Vacation Home so that the airline could win his support for airport improvements. That former chairman was also linked to the socalled bridgegate scandal in new jersey. United says it is cooperating with the investigation. And new frustration in europe as more refugees pour in from the middle east. Tempers flaring in hungary with hundreds again breaking through police lines near the border. That country will soon be deploying military forces. A half million refugees have now entered europe this year alone and today the head of the European Commission called for a redistribution plan that would require european nations to accept a minimum number of refugees. Back here in this country teachers in seattle are walking the picket lines on this first day of school. Contract negotiations broke down over pay, teacher evaluations and other issues. Thousands of parents are now forced to find alternative child care. A kayaker in the Pacific Northwest has quite a story to tell. Look at that. She came facetoface with a pod of orca whales. They swam beneath her and then right next to her. You can hear her there. The woman shooting the video says her hands were shaking so much she could barely hold the camera. Yet somehow she held on. We got this great video out of it. Finally pronouncing the names of cities and towns correctly is one of the challenges of our job being on live tv. But take a look at the name of one town in the uk. It is so big it barely fits on those signs, right . But last night on the news in england the weather guy decided he had to mention that town in wales because of its very high temperature. How did he do . Take a look. Just up the right from llanfairpwllgwyngyllgogery chwyrndrobwllllantysiliogogogoch the temperature got to 21 oh nailed it. But did you know that is only the second longest place name in the world. Youll tell us the first. Its in new zealand. 85 letters. Taumatawhakatangihangakouauauot amateaturipukakapikimaungahoron ukupokaiwhenuakitanatahu. Thats awesome. You wouldnt know if i said it wrong. The coolest part in weather we dont use the prompter so he was likely just saying it. You could see that smile on his face as he got it right. You too, amy. Way to go. Serena williams one step closer to that historic grand slam after a tough challenge from big sister venus last night. More on that in just 30 seconds. Biggest match yet at the u. S. Open. Lara, i know you were hanging on every minute. Every minute, george. It had it all, everyone. A sold out stadium. Celebrities galore. One sister competing against another for history so how would they react . All eyes on serena and venus in an electrified battle at the u. S. Open. The soldout crowd buzzing. Let these animals in. Celebrities jockeying for seats. So much on line for the greatest sister combo in the history of the sport. And all that was left was the tennis. And it did not disappoint. Big sister was the boss. 35yearold venus pushing her number one ranked 33yearold little sister to three sets. The two first met here at the u. S. Open in the 2001 final, venus took home the trophy then but this time serena was unstoppable. Serena williams, set and match. Her date with history still in check. Shes the toughest player i of prayed in my life, so and the best person i know. Reporter the little sister now just two matches away from becoming only the third woman in modern tennis to achieve a calendar grand slam. A feat last accomplished in 1988 by a then 19yearold steffi graf. When serena was just 6 years old. But she knows whatever is in her future her biggest fan will be there, cheering for her all the way. Ill always be the older sister. Thats never going to change. Shes really the best ever. Got chills again. Yep. I just love that. And she always is there for serena in that box cheering her on. And normally serena doesnt show that type of emotion when playing venus but she did last night so you know thats true. Much more ahead this morning, a terrified mother begging police to save her from her sons. The chilling 911 call from inside the home and investigation. And also, apples big reveal. The new products that changes the way you use your phone and tv and how to get big bucks for your old gadgets. Big reveal. The new products that changes the way you use your phone and tv and how to get big bucks for your old gadgets. Which means you can watch movies while youre on the move. Sitcoms, while you sit on those. And even fargo, in fargo binge, while you lose weight and enjoy a good cliffhanger while you hang from a. Why am i yelling . The revolution will not only be televised. The revolution will be mobilized. Introducing the all in one plan. Only from directv and at t. 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