Nightly news starts now. From nbc news World Headquarters in new york, this is nbc nightly news, reporting tonight, lester holt. Good evening. As we begin here tonight, Severe Weather is breaking out in several states across the south. Tornado warnings and watches are up within a big swath, including the dallasfort worth metroplex as well as Southeast Louisiana where a strong storm blew 18wheelers on their side late this afternoon. All signs point for americans across at least 13 states and were entering what is anticipated to be a multiday outbreak of violent storms. It will bring lightning, strong winds, hail, flash flooding and as many as two dozen tornadoes. Al roker is watching several spots at risk right now. Al, what have you got . We are seeing a very volatile situation. We are watching storms approaching louisiana. 8,000 lightning strikes in less than ten minutes. Were also seeing very strong storms developing. The areas in yellow are tornado watches and the areas in red, tornado warnings. Especially if kansas right now, a very dangerous situation. So for tonight, kansas hutchinson kansas, outside of kansas city also. Dallas, shreveport. 32 Million People at risk. This danger continues on into saturday and moves to the east, charlotte, atlanta, st. Louis, nashville and knoxville in the enhanced area. 32 million folks at risk for severe storms, large hail and damaging winds, torrential downpours and tornadoes, and this moves into sunday as well. Again, the same area. Oklahoma city dallas and on into san antonio. 16 million folks at risk, and weve got flash flooding possibilities anywhere from 3 to 5 inches of rain throughout parts of arkansas kansas and on down into louisiana, lester, and the danger is this is going to continue right on into early next week so flooding and a lot of damage expected this weekend. All right, al. Thanks very much. Now to a terrifying scene caught on camera. Dozens of students crowded on to a stage dancing and singing in a School Concert outside indianapolis when suddenly the stage collapsed sending the students plummeting into the orchestra pit below. Nbcs john yang has our report from westfield, indiana. Reporter it wasnt the big finish to the show of 80s music the students had planned. Dont stop the music reporter singing turned into screams as performers plunged 12 feet to the concrete floor of an empty orchestra pit when a temporary stage gave way in front of a packed auditorium. Thought it was planned. But it wasnt. And you hear the screams. People were running up to the stage trying to help people out. Reporter Officials Say 16 were treated for broken bones, torn ligaments and possible concussions. Late today the last one was released. Im sure no one in a million years thought this would ever happen. Reporter singer any control grishka had stepped off the cover of the orchestra pit just moments before it collapsed. When you looked down what did you see . I dont remember, frankly, because i immediately started crying. I remember hearing them screaming, which and hearing people say help me, which was just terrible to hear. Reporter musician omar santiago was the enthusiastic young man in the spotlight. It was instant. One moment i was celebrating and the next thing i know im down in the hole. Reporter today, federal, state and local officials are investigating looking at the schools maintenance records. We all want the same answers. Our Community Wants the answers. We want to make sure this never happens against here or anywhere. Reporter classes were held today but attendance was optional. Taylor knight was one of many cast members who fell and returned to school. We all just kind of hugged. And it was good to be with each other again. Reporter after a night that few will soon forget. John yang, nbc news, westfield, indiana. Tonight baltimores mayor and Community Leaders are pleading for calm as the city prepares for what may be its most massive protest yet over the death of a man who suffered a serious injury while in Police Custody and the commissioner is admitting to serious mistakes by his officers, including multiple failures to provide timely medical treatment. Nbcs tom costello continues to follow the story for us. Reporter today, confirmation from Baltimore Police that once freddie gray was arrested and placed into a police van arresting officers failed to put a seat belt on him. A violation of police policy. We know he was not buckled in the transportation wagon as he should have been. No excuses for that, period. Reporter also today, police said gray appeared to be talking and moving in the van until the third stop. Among the questions, was gray given whats known as a rough ride . Jarring stops and starts that might have caused his fatal injury . Forecast someone harmed fred gray, were going to have to prosecute them. So giving too much information to you on the front here may jeopardize that prosecution. Reporter in the six days since gray died of a spinal cord injury. Black lives matter reporter demonstrators have demanded answers. Among the protesters this week, entire families, including 11yearold david williams. Im worried about me dying. And im thinking about my neighborhood stretched out with crack, and i just dont want to die. Reporter now demonstrators are promising to ramp enup the pressure tomorrow. They want an end to the cycle of black men being shot down, having their spines broken and their backs broken. The people of baltimore are demanding this. Reporter but today, surrounded by civic and religious leaders, the mayor urged all protesters to remain peaceful. This community and this whole community is a community seeking justice for mr. Gray. So if youre going to come here, come to help us, not to hurt us. Reporter Baltimore Police are also asking for witnesses to come forward. By the way, five of the six offices have now voluntarily talked to investigators, one has not, and the Baltimore Sun reports tonight that over the past decade two suspects have won court cases against the city for being paralyzed while riding in those police advance. Lester . Tom costello in baltimore, thank you. Overseas, a stark reminder of the growing Terror Threat that hangs over so many european countries. Today a highly coordinated series of raids in italy resulted in the arrest of terror suspects in a network that had once plotted an attack on the vatican and even the previous pope himself. Nbcs chief Foreign CorrespondentRichard Engel has the details. Reporter the target of terror, reportedly Pope Benedict himself. A plot to target the vatican, italian prosecutors say, by a major Al Qaedalinked cell spanning italy, a cell broken up today with police raids in seven areas, recorded on police video. 18 arrest warrants, 9 sunts detained, 9 others still at large. The suspects are pakistanis and afghans. A key figure, prosecutors say, this preacher, arrested outside milan. It was a fundraising cell for al qaeda in pakistan, investigators say, in direct contact with osama bin ladens inner circle. Italy has been following this group for years, recording thousands of their phone calls. One investigator said thats how that 2010 plot against the pope was finally uncovered. This is a series of guys who are involved from sometime back. In some ways were seeing a Historical Network being disrupted now. Reporter italy these days is on edge, and its not alone. Since the paris terror attacks in january, s american, while president obama is reinforcing his faith in the nations spy agencies just one day after apologizing for that botched operation. Nbc esenior White House CorrespondentChris Jansing has more. Reporter president obama got a standing ovation today from members of the Intelligence Community and a hug from intelligence director james clapper, one day after revealing that a cia drone strike in pakistan accidentally killed american hostage warren weinstein. We all bleed when we lose an american life. We all grieve when any innocent life is taken. Reporter nbc news has confirmed that when u. S. Drones struck an al qaeda compound they expected to hit four terrorists but found six bodies. It would weeks before they could confirm weinstein and an italian hostage had been there, too. In a new statement today, weinsteins widow elaine thanked italian Prime Minister renzi for his message of condolence yesterday but didnt mention a phone call from president obama. Just yesterday she called some of the administrations assistants during her husbands captivity disappoint disappointing. There has been call for a hostage czar. Less. Its a government bureaucracy and i dont think were being as smart as we could be. Reporter its not an academic exercise. While the state department wont release exact numbers, its believed six americans are held overseas. Including crate line coleman who was pregnant when she was captured in afghanistan in 2012. In iran hekmati and levenson and austin tice who disappeared in syria with their families at home still waiting and hoping. Today the white house said it is considering something to a hostage czar and wont change its pollingsy of not negotiating with terrorists. Sometimes though a third party is used in these situations, and late today sources told nbc news thats how u. S. Officials were able to get medicine and warm clothes to weinstein during captivity. Lester . Chris jansing, thank you. A some ter 100th anniversary being marked around the world today remembering what pope francis recently called the first genocide of the 20th century, the massacre of 100,000 armenians during world war ii. Observes in armenia, throughout middle east and here at home where tens of thousands marched through a Los Angeles Neighborhood in little armenia to a turkish consulate waving turkish flags and signs making sure the world never forgets. Actress Angelina Jolie brought her star power to the United Nations to brick attention to the dire humanitarian crisis in syria. She did not mince words accusing the u. N. Of not doing nearly enough to stop the killing in syria or to help the millions who have fled the country or who have been displaced. We cannot look at syria and the evil that has arisen from the ashes of indecision and think this is not the lowest point in the worlds inability to protect and defend the innocent. Jolie is a special envoy for the u. N. On refugee issues. When asked about her briefing syrias ambassador was quoted as saying shes beautiful. There is an alert tonight about a growing outbreak of bird flu rippling through the u. S. Poultry industry. Now in 16 states with minminute latest to declare a state of emergency, 7 million chickens and turkeys affected since march, and the government is scrambling to figure out how to stop t. Nbcs Janet Shamlian has our report. Reporter the most significant bird flu outbreak in 30 years. Minnesota the latest to declare a state of emergency. Tonight, more protective measures, disinfecting vehicles at farms. Poultry producer amonbayer has 300,000 chickens and some of them are sick. I know what a healthy bird looks like, and these looked a little bit sick. Reporter his farm now under quarantine and a complete lockdown at Sunrise Farms in iowa. One of the largest egg producing plants in the nation. The entire flock will be lost, almost 4 million hens. Thats more than 1 of the egglaying hens in the u. S. Its pretty serious right now with the number of cases that were seeing and that were still continuing to see on a daily basis. Reporter highly contagious avian flu has now spread to 16 states. The usda calling it the biggest outbreak ever, the diss spread through the droppings of migrating birds can be fatal within 48 hours. Come here, chicks engs. Reporter mary an fortis runs blue star ranch in texas. Among the poultry farmers across the country whose birds for now are healthy. You know the avian flu is definitely something to be concerned about, so we do our absolute best. Reporter no cases of the flu have been reported in humans and the cdc says the risk is low, but the cost is skyrocketing. The 5 billion export market in trouble as mexico, russia and more than 50 other countries refuse poultry from affected states. Our food supply is safe. The fda says theres been no infected poultry or eggs that have been sold to consumers a growing catastrophe in the heartland threatening the nations poultry supply. Janet shamlian, nbc news, houston. Theres a lot more to tell you about tonight, that erupting volcano exploding nine miles high over two countries, now disrupting air traffic. Flights grounded and streets covered in ash like snow. Incredible new images coming in. Then, prepare your heart to soar. Later the little boy proving the skys the limit. A terrific story of a kid learning to fly with a little help from his dad. There are new evacuation orders for thousands living near that evupting volcano in chile now spewing ash and ash nine miles into the air, covering streets and seeping into nearby rivers. Nbcs Miguel Almaguer reports reporter mighty blast causing most of the damage and chaos in southern chile are spewing a steady plume of ash and toxic gas nine miles into the air now for three straight days. A tourist at a National Park captured the initial eruption. Whoa reporter encinada ten miles from the calbuco volcano is now a nomansland, a tiny town choking in ash. 1,500 people here forced to flee the dangerous air. No word on when they can come home. Chiles director of mining and geology says the volcanic activity could go on for weeks. With calbucos pulsating heat visible from space satellite images show smoke and debris drifting into argentina where lakes and beach res now coated in two inches of ash. Tourist towns are now a chalky mass. The border between argentina and chile is shut down and so are airports, terminals and runways an eerie government town some International Flights turning around midair to avoid the ash. American and delta suspending flights into argentina. Tony is stranded in costa rica. Theres debris all over the runway he says. Our flight is suspended. Tonight the winds are again blowing more ash from calbucos angry peak, a vibrant colorful region now coated in soot and ash. Miguel al malgier, nbc news. Were back in a moment to tell you how much the airlines are saving this year and how little of it is translating to your airfare. The Parent Company of nbc is in the news. Comcast announced its dropping its 45 million bid for time warner cable. The announcement comes after federal regulators raised concerns at combining the number one and number two Cable Companies would give comcast too much control over internet services. With 55 of all broadband subscribers in america. And today pepsi announced its dropping the artificial sweetener aspartame from diet pepsi, responding to falling sales of diet soda and concern from consumers. Both coke and pepsi blame the declines on Public Perceptions that aspartame, also known as nutrasweet isnt safe. However, the food and Drug Administration says more than 100 studies so aspartame is safe. That said, diet pepsi will now be sweetened with splenda starting in august. Lower fuel costs have led to big savings for airlines this year but not their customers. The four big carriers saved a combined total of 3. 4 billion in just the first three months of 2015 but average fares in the First Quarter for American United and southwest only fell 66 cents. Delta doesnt reveal fare information. When we come back the dad showing his toddler and the world that the sky truly is the limit. He claims hes hiding the height of murder. As storms move in theres concerns the rain will cause more problems than it solves. Story is a father and son and a little boy who is proving the skys the limit thanks to his dad. Amazing photos of him flying has gone viral, inspiring so many people. Nbcs Halle Jackson has their story. Reporter look right there. Photographer Allen Lawrence takes hundreds of pictures of his kids, but one of them is not like the others. Because of all the lawrence children only will flies. Will has always wanted to fly ever since he learned to roll over on his stomach. Reporter so one day dad made it happen, sending the photos to friends and family a change from when will was first born and allen didnt share any pictures. When the doctor told us he had Downs Syndrome i didnt want theme see him and know that he had downs reporter it took a wakeup call from his wife to help allen see beyond the Downs Syndrome diagnosis. I just had to say, buddy, we will deal with what comes our way, but right now hes healthy. Hes happy. Hes beautiful. Reporter and hes special because whether hes eating breakfast or a midnight snack, on the farm with his friends, his head in the clouds or his head in the game, will can gli, and he can dunk. Mostly kids just look at the pictures and they will turn and look at me and say can he really fly . Its magic, mostly. Reporter im simply just holding him and then i go into photoshop and brush myself out. Reporter on allens blog thousands of comments from other patients who appreciate this perfective. Really trying toil straight how he hasnt placed limits on our family. People with Downs Syndrome have so much to offer the world. It might be a heard journey for him, but he can do anything he wants to do. He can fly. Reporter and when will flies, he lifts all of us with him. Halle jackson, nbc news, paradise utah. Will and his pop giving us all a lift to end the week. Thats going to do it fours on this friday night. Im lester holt. For all of us at nbc news, thank you for watching and good night. Right now at 6 00 not much but its on the move. A storm is pushing towards the bay area right now. Thanks for joining us. Im raj mathai. And im jessica aguirre. It sounds odd but its really about to happen. Rain in the bay area midapril. Showing you a live look at Mendocino County as clouds and a few raindrops are starting to roll in. Mayor honda looks at bad news about the drought. Lets look at chief meteorologist jeff saniri. Well probably see showers about 10 00. Its all about the gusty winds. We know you felt it if you were outside today. If you planted any new trees in that wind theyre probably blowing over there if theyre a bay area root tree. Right now the winds at 20 miles per hour. The weakened storm system is now 250 miles away. Its picking up some steam and were beginning to see some raindrops here in extreme northern california. Again, not very heavy. Only fourth of seven inches at this hour. Mainly in napa and sonoma counties, then eventually a heavier zone of rain in santa rosa down toward san jose. In terms of the overall totals it looks like any kind of rainfall will be most beneficial across contra costa and