Cars overcome by large hail, neighborhoods turned white. The Severe Weather threat for easter sunday. And brackets burning. Half of the final four now decided. Villanova stunning kansas. The dive to the floor. The nailbiting victory. And oklahoma dominating the ducks for a huge win. The big matchups coming next. Good morning on this easter sunday. Happy holiday to everybody. Heres a look at the scene in st. Peters square where the pope just wrapped up his easter mass. Thats right. Happy easter to those of you preparing to go to services this morning, and our reporter on the ground there tells us the crowds are smaller this year sh, most likely due to nerves and fears surrounding the terror attacks in belgium earlier this week. Yeah, and there was news on that front overnight. Police in italy arresting a suspect accused of providing fake i. D. S to the killers. All of this on top of the arrest of this man in belgium. Hes a former freelance journalist. Many wonder if he is the same man who was caught on camera at the airport in brussels right there walking right next to two of the suicide bombers wearing the white jacket and black hat. Meantime, here at home, the families of this married couple from kentucky had their worst fears confirmed overnight. Abcs Alex Marquardt in brussels with more on that and the latest in this fastmoving investigation. Good morning, alex. Reporter good morning, paula. Thats right. More sad news this morning. The belgian authorities have been slowly identifying the names of those 28 killed in the attacks. That american couple had been unaccounted for all week. Now they have been confirmed to have been killed. This as authorities all across europe step up the hunt for anybody involved in tuesdays attacks. Overnight, justin and stephanie shults, an american couple from kentucky missing since the brussels attacks, now confirmed to be among the dead. They had just dropped off stephanies mother at the airport when the explosions went off. As the news of their deaths came, justins brother tweeting, go rest high on that mountain. Now the first charges since the attack that killed 28 have been handed down. The most important, against this man, in custody since thursday. Faycal cheffou. Charged with terrorist murder. This video shows some of his work as a freelance journalist. This morning, abc news has learned he had been detained in the past for trying to recruit refugees for jihad. But is he one of the two unidentified suspects who managed to slip away . This man in the hat at the airport with the suicide bombers or another man seen with the suicide bomber at the metro station before he struck a train. Authorities have also released this photo said to be of a syrian man believed to have been complicit in tuesdays attacks. The links between brussels and paris now even stronger. That airport suicide bomber on the left is the alleged bombmaker for paris. The list of suspects and possible accomplices growing, security agencies across europe on the lookout. In italy overnight, an algerian man, wanted by belgium, was arrested for making fake documents for suspects involved in the paris attacks. Now, almost daily reports of arrests and raids to capture those involved and prevent more attacks. The new normal in europe. And youll remember that after the paris attacks, there was the solidarity march. They were trying to replicate that here this morning with a march against fear. Unfortunately, that march has been cancelled. The police saying they simply didnt have the manpower to keep it safe. Dan . Hard to miss the symbolism there. Alex, thank you. And as we said at the top of the show, the shadow of terror is hanging over all of europe on this easter sunday. The vatican on high alert as thousands of people gather in st. Peters square to hear pope francis say mass. Abcs matt gutman is right there. Matt, good morning to you. Reporter good morning, dan. Thats right. In a day that seemed so heavily influenced by the threat of terrorist attacks, the pope made mention of terrorism across the world, but only briefly seeming to make a point of not dwelling on that, instead focusing on todays festivities. By the thousands this morning, they filed toward st. Peters square through batteries of metal detectors into the heart of catholicism. This morning, pope francis celebrating easter mass with tens of thousands, giving communion, and praying for peace. His remarks referencing the attack in brussels, but also other terrorist attacks across the world. [ speaking a Foreign Language ] saying, our world is full of persons suffering in body and spirit even as the daily news is full of stories of brutal crimes which often take place within homes and largescale Armed Conflicts which cause indescribable suffering to entire peoples. He also railed against the mistreatment of the poor, the plight of immigrants, those persecuted for their faith and the environment. Pilgrims, nuns, and tourists craned for a better look at the pope. This trio from ireland resting after the long wait to get in. Children perched on parents shoulders. Amidst the ceremonial swiss guard and military marching bands, there were squads of vigilant security officers. But the faithful undeterred by the ongoing threat of terrorist attacks. Is your head on a swivel while youre Walking Around the streets . I mean, yeah, it has got to some of the people in our program. Like our roommate, some of them are at home because they or their parents didnt feel comfortable with them coming. Reporter so far this morning, everything seems to have gone smoothly here. The security lines went pretty quickly, but the one thing that not everyone expected, all this empty space in st. Peters square. The pope even zipping around in his popemobile smiling as he waved and blessed the crowd. It is the culmination of holy week, which includes the annual event of pope francis washing the feet of both catholics and noncatholics. And toward the end of mass, the crowds certainly seemed to fill in. And as the ceremony was ending, we saw the pope zip by in the popemobile outside the security bubble of st. Peters square, perhaps thumbing his nose at isis and all those security threats. Paula. Great, matt gutman, thank you from rome for us this morning. And to politics now, and Bernie Sanders swept the night with convincing wins in alaska, hawaii, as well as washington. Those victories also underscoring Hillary Clintons continuing vulnerabilities within her own party. But will these delegates that sanders racked up mean much . Abcs devin dwyer is in washington for us to explain this morning. Hi, devin. Reporter good morning, paula. Hillary clinton is still the clear frontrunner in the democratic race. But for Bernie Sanders, it was his biggest day yet showing the enormous enthusiasm for his campaign. It was a blowout for bernie. We just won the state of washington [ cheers and applause ] reporter Bernie Sanders sweeping the democratic caucuses in washington, alaska, and hawaii by huge margins over hillary clinton. So dont let anybody dont let anybody tell you we cant win the nomination or win the general election. Were going to do both of those things. Reporter sanders claiming momentum after a string of 10,000plus megarallies from the west coast to wisconsin. All bernie, bernie, bernie. Reporter no comment on the losses from clinton, who is taking the easter weekend off. Clinton dominates the delegate race. She needs to win just roughly a third of those still up for grabs to clinch the nomination. Sanders needs more than double that. Meanwhile, republicans are engaged in an ugly personal dispute. Donald trump off the campaign trail for easter firing tweets at rival ted cruz. Lyin ted cruz is now trying to convince people that his problems with the National Enquirer were caused by me, trump tweeted. I had nothing to do with the story. Cruz says those tabloid rumors of marital infidelity are a plant. Striking back at trump, tweeting, donald trump is no republican, and hes certainly no conservative. The gop race now turns to wisconsin, the next big primary in just nine days. All the candidates will be off the campaign trail today for easter. Many of them attending Church Services with their families. As for the man already in the white house, president obama, hes expected at church today, too. Dan . Devin, thank you. Lets bring in abc news chief White House Correspondent jon karl, who will be hosting this week later this morning. Jon, good morning. Lets start with the democrats. How much do yesterdays victories for Bernie Sanders really change the dynamic of the race . Does sanders now have a substantially improved shot of winning the nomination . Hes still got an uphill battle, dan, but just look at what he did. These werent just victories. These were out and out landslides. But if you look at the delegate math right now, dan, Bernie Sanders would need to win 73 of the remaining delegates to clinch the nomination. That is a virtually impossible task, but ill tell you what to watch next, the New York Primary on april 19th. Sanders will now make a big push to win in Hillary Clintons backyard. Yeah, new york and pennsylvania are going to be key, key spots in the democratic race. Lets talk about the republicans, though. In his report devin dwyer mentioned that the primary in wisconsin is coming up next tuesday. How key is wisconsin on the republican side . Well, its very important if donald trump can win big in wisconsin, he goes a long way towards clinching the nomination before the republican convention. If ted cruz can pull out a win or keep it really close, what youll see is highly more likely that well see a contested convention in july in cleveland and what a show that would be. And almost certainly much more nastiness. Jon karl, thank you. And i want to remind everybody, jons got a big show this morning. Hes going to go oneonone with donald trump and Bernie Sanders. Thats coming up on this week right here on abc later this morning. Paula, over to you. Its going to be a good show. Thanks, dan. And now to a shocking airport arrest. An American Airlines copilot was pulled from his flight shortly before takeoff, busted for allegedly drinking. And it was a quickthinking airport agent who turned him in. This flight was scheduled to fly from detroit to philadelphia. And abcs Marci Gonzalez has more. Reporter an American Airlines copilot arrested, accused of failing two breathalyzer tests moments before the plane he was at the controls of was scheduled for takeoff. I was getting a little nervous, and i guess there was a good reason why now. I was speechless that Something Like that could happen. Reporter passengers on board, many of them spring breakers, heading for the caribbean, at first told there was a problem with a cockpit seat. One of them finally spotting this scene and snapping a picture of a man in handcuffs believed to be the copilot. First i saw just a police car, and i thought, wow, thats odd. About five minutes later, i saw them handcuffing him. Reporter the tsa saying one of its agents smelled alcohol as the pilot passed through security and notified police. This is a drunk pilot. He could have taken the lives of at least hundreds of people. Reporter officials have not revealed his blood alcohol level. If you show up with anything in your blood, whether its drugs or alcohol, your chances of being caught are extremely high. Reporter American Airlines saying it is helping investigators writing in a statement, the safety and care of our customers and employees is our highest priority. For good morning america, Marci Gonzalez, abc news, new york. All right. Crazy story. Very crazy. But so grateful for that quickthinking tsa agent. Absolutely, absolutely. We want to say happy easter to ron. Ron, i know youre keeping track of all the other stories. Thanks very much. Good morning to you paula and dan. Good morning, everyone. We begin with a raging wildfire that has now spread from oklahoma into kansas. The blaze has already charred more than 600 square miles and destroyed at least six homes. Military helicopters have been called in to help battle that fire. Four black hawk choppers from the Kansas National guard have been deployed this weekend. At least two of them have 660gallon buckets that can dump water onto the flames. Officials say the wildfire is already the largest in kansas history. And in alabama, investigators are trying to figure out what caused the fatal crash of a medevac helicopter. The chopper went down in a field on saturday while ferrying a man who had just been injured in a car crash to a hospital. All three crew members and the patient on board were killed. A routine Fire DepartmentTraining Mission off the coast of San Francisco ended up turning into a real rescue mission. Rough waves causing the firefighters boat to overturn sending all seven firefighters into the chilly waters. Some nearby fishing boats and the coast guard helped bring the men to safety. Four of the firefighters, though, were hospitalized with minor injuries. And actor robert deni niro has decided to pull a controversial antivaccination documentary from its annual tribeca film festival. The actor had come under intense criticism for backing the film that links childhood immunizations to autism. A terry wildly debunked by medical researchers. De niro who has a child with autism, said he had thought the documentary would start a conversation about a film that is deeply personal to him. He says the film does not contribute to that discussion. From our ever growing file, a brazen burglary at a tampa car dealership. Watch as two of the suspects break into the office through a window, then they rummage through the desk drawers. In one of them they found the box of car keys, and then they go outside where theyre joined by more alleged suspects. Everybody tries to match the keys to the car. Successfully does that and then a minivan, one of them getting away with crashing through a gate. To clear the way. The thieves, the alleged thieves, dan, getting away with eight automobiles. I dont think we need alleged here. Maybe youre right in this case. On camera. Im not a lawyer. I dont think we need to say alleged in this case. And finally, a happy ending for a man who became known as sad grandpa or pawpaw. The photo of kevin harman went viral earlier this month when it was tweeted by one of her grandchildrens when she was one of only six of his grandchildren to show up for a burger dinner. Yesterday he was anything but lonely. At least 100 people from around the country showed up to eat burgers with him. The burgers cost 2 bucks, and you could also purchase a tshirt with the message, i ate a burger with pawpaw. The commercial possibilities are endless. Pawpaw chain of burgers and maybe even a book. A 2 burger . Yeah, 10 hungrier. Somebody was charging 2 bucks for a burger. Thats actually a pretty good deal. What if you wanted a double . Well ask pawpaw that. I love america. Turn your misery into a commercial opportunity. Yeah, exactly, exactly. Thank you, ron. Lets talk sports now. After all the bracketbusting, march madness now coming down to the wire. Thats right. By the end of today, the final four will be set. So far, two teams have punched their ticket. Two more will later today. And espns tony reali is telling us who is in it to win it. Mason wants the three, puts it up, oh reporter overnight, after a knockdown, dragout battle. Look at the pirouette delivery. Reporter onehalf of the final four is locked in. Villanova stunning the heavily favored kansas jayhawks in a march madness nailbiter. The wildcats clawing back from a fivepoint deficit. Going to load up a three, and he buries it. Reporter trading big buckets down the stretch. Takes him to the paint. Puts it up lefthanded. Reporter senior and birthday boy Ryan Arcidiacono knocking the ball away from kansas in the final moments. Two freshmen sealing the deal. Mikal bridges diving to the floor to prevent the jayhawks from any chance of tying it up before Jalen Brunson sank the games final two points at the Charity Stripe sending the wildcats to the final four for the First Time Since 2009. Best birthday present ever. I just love everything about this university. Reporter that win destroying what is left of a landscape littered with ruined brackets in this years tournament. 25 of brackets picked the jayhawks to win it all including president obama. Im putting kansas in here. Reporter their challengers in houston, the oklahoma sooners. Are we surprised . Reporter superstar buddy hield continuing to elevate his game scoring 37 big points, sinking three after three after three dominating the oregon ducks soaring to a 12point victory. Buddy hield reporter what they said. Buddy hield is going to be the National Player of the year this year. But somehow hes been better in this tournament drawing comparisons to steph curry. Theres not a better comparison than being compared to testify curry, as you know. Hell meet Ryan Arcidiacono in the final four of villanova. Buddy and arcidiacono, thats like a buddy cop movie at least or words with friend. Tonight well find out exactly how the other half will live in the final four. Well see if the number ones strike back. North carolina is a favorite over notre dame. And virginia versus upsetminded syracuse. You were particularly prescient about the oregon oklahoma game. You said somebody with an o is going to win it. I thing getting half is good. Just the good half, there we go. Paula just wanted to show she knows what the word prescient means. What are you talking about . I think i taught that word to you. You might have. Im particularly observant this morning. Dan. You are. You are. Rob, whats cooking in the Weather Department . Hey, listen, speaking of march madness, check out this video out of central florida. Look at the hail piled up here. In some cases, onefoot drifts. Meaning, you know, some of the