Teachers in mississippi now in quarantine after more than 400 people test positive. A Key White House Coronavirus Task force member joins us live. Abc news exclusive. The former high ranking trump official with harsh words for the president. The president wanted to exploit the department of Homeland Security for his own political purposes. He says what he witnessed the president do was terrifying. Hes now breaking republican ranks and endorsing democratic nominee joe biden. Miles taylor joins us live. Ellens emotional apology as three Top Producers all accused of Sexual Misconductir fre. Ed the talk show host reportedly addresses her staff, apologizes over accusations her show created a toxic work culture, taking on rumors about herself calling them crazy and not true. And the bellas are back. Banks, kendrick, wilson and more reuniting for a perfect new rendition of beyonces hit song. Plus, how theyre pitching in for a good cause. Always great to start the morning with some beautiful music like that. Good morning, america. Great to be with you on this busy Tuesday Morning, george and michael. I thought you were going to say beautiful faces like george and i. But i guess music is better than our faces. How about that . We do have a lot of news to get to. Well start with that big night for the democrats kicking off the National Convention like weve never seen before, george. A Virtual Convention in this time of social distancing. The democrats theme is unity, we, the people. And the speakers spanned a wide spectrum. Progressive champion Bernie Sanders, highprofile republicans and the nights headliner, Michelle Obama, who delivered a fierce takedown of President Trump, high praise for the empathy of joe biden and an emphatic plea for everyone to vote. Mary bruce starts us off. Good morning, mary. Reporter good morning, george. Well, this was a passionate condemnation from Michelle Obama. She is one of the most Popular Figures in american politics and she came out swinging on night one declaring that President Trump is in over his head and warning that the crises facing this country will only get worse if he is reelected. Michelle obamas message summed up in the words spotted on her necklace, vote. Overnight, in clear terms, Michelle Obama breaking down the stakes in this election. Let me be as honest and clear as i possibly can, donald trump is the wrong president for our country. He has had more than enough time to prove that he can do the job, but he is clearly in over his head. He cannot meet this moment. He simply cannot be who we need him to be for us. It is what it is. Reporter the former first lady setting the tone for the convention and reinventing her famous motto, when they go low, we go high. But lets be clear, going high does not mean putting on a smile and saying nice things when confronted by viciousness and cruelty. Going high means standing fierce against hatred while remembering that we are one nation under god and if we want to survive, weve got to find a way to live together and Work Together across our differences. Reporter growing emotional, Michelle Obama with a call to decency. This is who we still are, compassionate, resilient, decent people, whose fortunes are bound up with one another and it is well past time for our leaders to once again reflect our truth. Reporter democrats kicked off their convention eager to show a united front. Its up to all of us to help make joe biden the next president of the United States. Reporter in a live address senator Bernie Sanders urged his progressive supporters to back biden. Let us be clear, if donald trump is reelected, all the progress we have made will be in jeopardy. At its most basic this election is about preserving our democracy. Reporter and in an attempt to show that biden can speak to all americans, the night featured prominent republicans too like former Ohio Governor john kasich who ran against trump for the republican nomination is 2016. Joe biden is a man for our times, times that call for all of us to take off our partisan hats and put our nation first for ourselves and, of course, for our children. Reporter democrats also highlighting the voices of americans impacted by the crises facing this country like Kristin Urquiza who lost her father to the coronavirus and blames the president. My dad was a healthy 65yearold. His only preexisting condition was trusting donald trump and for that he paid with his life. Reporter she made it clear this election will be a referendum on the president. This convention is unlike any other. Instead of an inperson gathering in milwaukee this is the center of the action, the cheering crowd replaced with choreographed videos and virtual speeches. Live and taped. Now, the president just responding on twitter to the former first lady saying, quote, somebody please explain to Michelle Obama that donald trump would not be here in the beautiful white house if it werent for the job done by your husband, barack obama. George, clear from the president s twitter feed he was watching closely. He is ready to go. Mary, thanks very much. Im joined by one of joe bidens rivals during the primary, the former mayor of south bend, indiana, mayor Pete Buttigieg. Mayor pete, thank you for joining us again this morning. You just heard the president taking on Michelle Obama and president obama also saying that joe biden is basically going to be a trojan horse for socialism after the convention. Whats your response . I guess when we go high, he goes low. Its not terribly surprising, but its clear from the message we heard last night where the character of america could be. Michelle obamas message was powerful. All the messages last night were powerful. The simple fact is that most americans are with us. We are winning for a reason. Doesnt mean were guaranteed to win. We got to put in the work. But this president is exceptionally unpopular. Hes losing ground and thats because right now the American People want a way out of the chaos, of the division and the simple incompetence that has characterized this presidency especially in this crucial year. You talk about getting to work. The core message of Michelle Obama, one of them was, people have to get out and vote early, go in person if you have to. It seems there is real concern there that these attacks on mailin voting from President Trump might be working. Absolutely. I mean what, weve seen is that President Trump has realized that if the American People vote, he will lose and instead of a strategy of trying to convince more americans of his vision, his strategy is for fewer americans. He says hes only going to lose if the election is rigged. That is an attack on democracy itself. Hes going to lose if more people vote for our candidate, which on todays facts is exactly whats going to happen. And since when do you preemptively call into question the legitimacy of an election that you say by definition wont be legitimate unless you win. You got to understand thats not just an attack on the democratic party. Thats an attack on america. When the president of the most consequential democracy on earth in the last 2,000 years does Something Like that, thats bad for democracy around the world and just one more reason why you dont have to be a diehard democrat to know that we need a change in the oval office and it cant come soon enough. Democrats tried to erect a big tent last night. You had republicans like john kasich speaking, Bernie Sanders speaking. But a lot of progressives seem unhappy with the highlighting of republicans like that. Is there a real tension there . How do the democrats solve it . Theres always going to be in our big tent a tugofwar, always going to be internal jostling. But lets be clear, our party was unified. Last night you heard from republicans, former republicans, all the way through to Bernie Sanders, all offering the same compelling message that weve got to vote for joe biden and Kamala Harris for the sake of the country. Look, we will always continue to have differences of opinion inside our party on exactly how to do things like meet the climate challenge and raise wages and get Everybody Health care and defeat this virus. But the question thats going to be settled in november isnt over exactly how to do those things, its whether were going to do those things at all and everyone in our party and a lot of independents and some republicans, frankly, most americans agree on that question. Finally the Trump Campaign also launched overnight a new attack and most direct attack yet on joe bidens mental fitness. How big a concern is that . The president of the United States marked it as a great achievement when he passed a dementia screening. Look, this is not productive territory. We need to talk about where the country is headed and the president will continue to try to distract us from that. But its a losing, failing strategy at a moment when americans dont need anything more than the confirmation of our own everyday lives and experiences to tell us that america is on the wrong track and we need change fast. Pete buttigieg, thanks very much. Thanks. Well have full coverage of the Democratic Convention at 7 00 p. M. On abc newslive and ill angel our primetime coverage at 10 00 eastern right here on the network. Robin . And, george, after the convention, world news tonight anchor david muir and i will sit down with joe biden and Kamala Harris for their first joint interview. You can see that on sunday, 8 00 p. M. Eastern. Right now were going to turn to the latest on the coronavirus emergency and the two Largest School districts in the nation gearing up to safely reopen their doors to students and staff. The massive testing effort getting under way in los angeles. Our chief National Correspondent matt gutman went inside one of those classrooms getting ready for students to come back. Good morning, matt. Reporter hey, good morning, robin. Starting this week the l. A. School district will begin testing nearly 800,000 students and staff in what is arguably the biggest such initiative in the country. The superintendent here told me that he doesnt know exactly how hes going to pay for it all but he knows that with 80 of his students relying on schools for meals, hes got to get kids back in the classroom as quickly as possible. This morning, the l. A. School district, the second largest Public School district in the country, is launching what could be the most ambitious School Testing and Contact Tracing initiative in the nation. In some ways this is uncharted water. Almost flying by the seat of your pants. Were trying something that has not been done. Reporter the School District aiming to administer regular covid tests to its 700,000 students and over 75,000 staff. The goal is to get students who will be starting the year remotely back inside schools so to establish a baseline to keep track of any potential infections and growth. So there will literally be a clinician standing outside the gate of the School Monitoring in real time . Even more than that. We will be giving you an appointment to be tested. You will do a selftest at home. Pcr tests or antigen test . Pcr, gold standard. We have two types. Nasal swabs and swab in the check. The nasal are cheaper. Were going with an Innovative Lab at a price which makes it feasible. Toayy is gngo me from alteate esnt ke sen reporter of the country abc news is getting a look at some of the changes at the nations Largest School district, new york city, which include electrostatic sprayers and redesigned classrooms with fewer desks. Its opening to students part time despite protests from the teachers and principals union. It took a lot of work. Reporter Michael Mcdaniels is a fourth grade teacher in tampa. They had their first day of school there yesterday. He says considering the circumstances, it went well. The kids dont seem too bothered by the masks. The trouble they seem to have the most is giving each other space. Theyre so used to being right next to each other. Reporter other places are struggling with opening up. Overnight mississippi announcing over 2,000 students and nearly 600 teachers are now in quarantine after more than 400 students and teachers tested positive. At the university of north undergraduate classes are shifting to Remote Learning after about 130 students tested positive. Now, the key to testing here is going to be the speed of results and the district tells me itll probably get results back within hours or overnight which means it wont have to close down an entire school but perhaps a pod or single classroom. Robin . Okay, matt, thank you. In our next hour a key white house Task Force Member will join us live with much more on the testing. Michael . Cant wait for that, robin. Now we turn to the raging wildfires in california, scorching tens of thousands of acres as firefighters battle the flames in tripledigit temperatures. Will carr has the latest on the critical situation. Reporter californias facing a onetwo punch with millions in the middle of an intense heat wave. The fire here growing overnight. Two firefighters sustained minor injuries. Napa countys hennessy fire causing Widespread Evacuations as the fire has not been contained. California Highway Patrol tells abc news they received multiple calls of smoke and flames after lightning strikes in surrounding counties, although officials have not said what might have ignited the fire. There have been lightning strikes in the area in just the past few minutes. Reporter jeff defying those mandatory evacuations hoping to preserve his familys 130yearold winery as the fire begins to hit his property. If the fire gets a little closer, we have the hoses out and ready to make a stand. Reporter nearby resident phillip taking matters into his own hands, putting sprinklers on his roof as he sits on his porch watching the smoke billowing over the trees. Overnight the lake fire is now over 19,000 acres. That fire has been burning since last wednesday destroying a handful of structures and homes. This one is especially challenging given the hot, dry conditions and the rugged roadless areas were dealing with. Reporter crews have been setting backfires on the hillside behind me, essentially fighting fire with fire as the sun comes up and its going to be another scorching hot day today. Michael . All right, will, we hope they can contain it. Thank you so much. Turning now to the nba playoffs tipping off inside the disney world bubble. Will reeve has the latest on the competition. Reporter this morning, the nba playoffs are back. The pandemic making everything around the game different. Virtual fans cheering on their teams, players socially distanced and coaches Wearing Masks on the bench, everyone involved living and chasing a championship inside a bubble. But on the court, it was game on. Utah jazz allstar Donovan Mitchell recovered from his bout with covid19 months ago dropping 57 points. Oh reporter third most alltime in a playoff debut. The mavericks luka doncic also set a record for points scored in a playoff debut but the mavs still lost to the clippers after star Center Kristaps Porzingis was ejected from the game. The celtics edging out the sixers. Boston star jayson tatum giving his young son a postgame shoutout. I miss, you dude. Reporter 16 teams remain in the bubble. Going on over a month now, isolated from their families, loved ones and Close Friends allowed to enter the bubble at the end of the first round. Each player allotted one guest room. But until then raptors star kyle lowry getting a special intro from his boys. Number 7 both kyle lowry reporter the bubble has been working so far. There have been no positive tests in 42 days and tonight lots to look forward to. Lebron james and the top seeded lakers taking on red hot Damian Lillard and the portland trail blazers in prime time. Guys . Creating a lot of excitement. I love how they incorporated the kids. Following a lot of other headlines including our abc news exclusive with President Trumps former Homeland Security chief of staff. Hes now calling the presidency terrifying. Hes standing by live. And a break in a cold case murder after nearly two decades. We have the latest in the two men charges. First lets go to ginger. Hey, ginger. Michael, some in the southwest have called it the nonsoon season because there hasnt been much of a monsoon season. Bad for dust storms. That was moving south of phoenix with 50 plusmileperhour winds. You had record highs from pocatello, idaho at 100 to tucson and las vegas and i think today under t