tonight on "nightline," second strike. a new line of deadly storms is raking the midwest. oklahoma, dallas and now joplin, missouri, already shredded by loss. we'll have the latest. and, the heartwrenching search for the missing. >> it's just the not knowing that's killing us. plus, courtroom shocker. lawyers for murder defendant casey anthony deny she killed her young daughter and mount a stunning defense. pointing a finger in a direction nobody expected. and, life after dancing. after being voted off "dancing with the stars," supermodel petra nemcova headed as far offstage as you can imagine. we went along with her on a remarkable and heartwarming journey.

>> announcer: from the global resources of abc news, with cynthia mcfadden and bill weir in new york city, and terry moran in joplin, missouri, this is "nightline," may 24th, 2011. >> good evening, i'm cynthia mcfadden. we begin with more deadly weather. a giant storm system with multiple tornadoes inside it is moving across a wide swath of the midwest and south. our abc news desk has been monitoring all night. we're going to start there with the very latest. >> we are getting reports this morning of a massive tornado touching down in johnson county, arkansas, ripping through the small town of denning. just the latest in a strong of severe weather tonight, including major hailstorms in dallas that shut down the rangers/white sox baseball game for hours. tornado sirens went off again in joplin, missouri, with twisters touching down in kansas and oklahoma, leaving at least seven dead and dozens injured.

matt gutman was in oklahoma with a group of storm chasers. >> reporter: tornados again thrashed through this part of the country. the deadly funnel clouds left giant swatss of destruction. large tornado on the ground. local station koco was on the air as one of these tornados forked. >> this will be north of canton, tornado with debris. >> reporter: and we were on the ground. the discovery channel storm chasers zee rowing in on that same tornado. barreling down country roads at 80 miles an hour in the dominator, this tank-like vehicle that seems designed for a mad max movie. >> that tornado is picking up everything in that field. leaves, pieces of trees, branches. it so is powerful you can see a second vortex forming to the side of it. as surely as the seasons change, the storm chasers appear. >> majority of storms move slightly to the northeast.

east 95 northeast. this is moving away from us a little bit. it is large and in charge. right now, gentlemen. >> reporter: oh, my, you -- look at the size of that. >> she's really coming together. >> reporter: this spring has been particularly good for the storm chasing business. their office is the 700,000 square miles that make up tornado alley. why would anybody in their right mind drive into the center of a tornado? >> who said we're in our right mind? >> it's mother nature's last great mystery. there's still so much unknown. about tornados. we don't know how they're formed. we don't know why some super cells put down tornadoes and others don't. >> reporter: our driver stopped because we found ourselves directly beneath a cloud formation beginning to swirl into a tornado. >> right there is the funnel. it's going to hit the ground, facing northeast and the storm is headed northeast. it's going to head in that direction. >> reporter: you see the funnel forming right now. and feel the wind kicking up, as well. got to get back in. >> baseball hail!

>> this is what you call the bear's cage. that's where the tornado can drop down at any moment, any place, any time. yeah, we -- you guys are now members of the zero meter club. you've been zero meters from a tornado. >> reporter: with more storms in the coming days, these chasers will continue to be in hot pursuit. for "nightline," i'm matt gutman in canton, oklahoma. >> terrifying. stay safe, matt. as we said earlier, joplin, missouri, the town shattered by a tornado sunday once again under severe warning tonight. 124 people now confirmed dead. sunday's storm has been upgraded to an ef-5 tornado, meaning winds greater than 200 miles an hour. my co-anchor terry moran spent the day there as the city digs out. we spoke to terry earlier tonight before he and our crew were told they had to take shelter. >> reporter: cynthia, this was a day where the full horror of

what happened here in joplin sunk in on the people here. it was a day when you saw across this devastated landscape, people coming back, picking through the rubble, looking for something, anything they could save. and it was a day when the tragic searches for the missing, many, many still unaccounted for, continued right through this rubble, search and rescue teams from across the country looking for signs of life and for victims. today in a landscape of utter destruction, the people of joplin, missouri, desperate, yet determined, stirred back to life. 30% of this city is simply gone. blasted into bits by the monster tornado. for the survivors, it is a time of coming to terms with the trauma they have been through. >> seeing this right now, i'm in shock. i can't even -- it doesn't even look the same. it's just -- it's hard to believe that i made it out of this alive. >> reporter: bailey knight worked at the walmart in town, which is now in ruins.

there were several people killed here. she got out, scrambled up over the twisted metal and wreckage and emerged into a nightmare, searching for her loved ones. >> i was by myself and i was walking down these streets and i was just trying to get to them and trying to stay calm, because there were so many people that were injured that i saw and i just had to know in my heart that my mom was going to be okay. >> reporter: she was okay, but so many were lost. and the difference between life and death, sometimes, was a matter of a few feet. this was a payless shoe store and this street over here marks a kind of border. on one side, it's gone. on that side, they made it. in the faces of the children, you can see how strange this must be. man. their home is gone. their town is gone. their world turned upside down. this was your living room?

>> yes, it was. >> reporter: we met tyler and amber hayden and their kids, picking through the rubble of what was their new home. they consider themselves blessed, though, as if someone was watching over their young family. because when the storm hit, they held each other and survived. >> all five of us came back and got in the closet. >> two of you and three little ones? >> we were underneath the blankets and the pillows back there. you can see where it kind of started to come up there. and he was holding this door shut from the inside. >> reporter: you could feel it -- >> i had my feet on both sides of the door frame and had my hands on the doorknob, keeping it from pulling. >> reporter: like strangers in a newly strange land, the survivors came home to the destruction zone, looking for something, anything, to salvage. it's all gone, though. let me give you a sense of the scale of the destruction here in joplin. out there in the distance that is the wrecked hospital.

everything between there and here is obliterated, just gone. the storm, like a bomb, just destroying this entire part of the city. >> reporter: there was good news in joplin today. two more survivors were pulled from the rubble. but today was really a day of the missing. of the lost, but not yet accounted for. stephen campbell is looking for his wife, tammy, who was lying next to him when the tornado hit. >> i heard her scream. right after she screamed that's when the whole thing collapsed on us. that was the end of it. >> reporter: it's almost unimaginable, the not knowing. rob and brandon getz are looking for rob's mother. brandon's grandma. tedra kune. she's 70 years old. bright blue eyes and a fondness for the local casinos. and she lives alone. that was her apartment. >> this right here was my mother's -- >> reporter: oh, my god. >> this is the only identifiable piece of merchandise i can find

that was hers. and that bathtub was hers. >> reporter: so, there's been search and rescue through here, there's been dogs -- >> there's been us, search and rescue, dogs, they've taken camera probes, probed them in every corner. the last word i heard, there was two ladies taken out but neither one of them was my mother. >> reporter: so, there's no sign of her? >> no sign of her. it's like she was just -- she just disappeared. >> reporter: brandon walked for miles from his home the night of the tornado to look for his grandmother. he and his dad have searched for two days, here, at the morgues in the hospitals, in the shelters. brandon struggles to hold it together as he tries to explain to us what it's like when the worst happens to you. >> i don't even know how to put it into words, i mean, how do you explain this to somebody who hasn't seen it? it's just unfathomable. >> reporter: so much is lost here. so much is missing. and so much will never be the same.

so many people are hanging on to hope, but that hope diminishes hour by hour as the chances of pulling people out of the rubble diminish, as well. the rebuilding effort, they're already talking about will take years. right now, however, people are concerned about just getting through the next few days. cynthia? >> just heartbreaking. terry moran reports. the storm is projected to hit memphis and st. louis tomorrow. stay with us. ooh, a brainteaser. how can expedia now save me even more on my hotel? well, hotels know they can't fill every room every day. like this one. and this one. and oops, my bad. so, they give expedia ginormous discounts with these: unpublished rates. which means i get an even more rockin' hotel, for less.

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depend® colors for women. looks and fits like underwear. protects like nothing else. depend®. good morning. great day. >> announcer: "nightline" continues from new york city with cynthia mcfadden. >> in the summer of 2008, the story of 2-year-old caylee anthony made tabloid headlines

when the little girl went missing, prompting a massive search effort. eventually the girl's mother, casey anthony, was charged with her daughter's murder. ashleigh banfield was in court today for opening arguments as the story took yet another shocking turn. >> reporter: bomb shell day in court as the defense team unveiled its answers to a 3 tleerld mystery. who killed caylee anthony? and why did it take casey 31 days to say anything about it? >> well, the answer is actually relatively simple. she never was missing. caylee anthony died on june 16th, 2008, when she drowned in her family's swimming pool. >> reporter: as if that defense were shot shocking enough, casey went on to point the finger at her father, george anthony, suggesting he was there when caylee died and threatened casey. >> look what you've done! your mother will never forgive you and you will go to jail for

child neglect for the rest of your life. >> reporter: jose baez pushed even further, suggesting her father played a role in disposing the child's body. and when it came to explaining the web of lies that casey spun in the following weeks? she claims she was molested by both her brother and her father. >> when casey was 8 years old and her father came into her room and began to touch her inappropriately. casey was raised to lie. >> this is a bomb shell. for the defense to putthe finger at her father, that's a very aggressive and potentially dangerous defense. >> reporter: dangerous, because both her father and her brother had denied the allegations and casey still has to explain photos like these. they were taken while this tragedy, as the defense puts it, was snowballing out of control. >> so, i go through day 21, and casey anthony is just galavanting around orlando.

day 26, casey anthony's back at fusion. the flight club. >> it's going to be very hard to convince a jury that part of the grieving process here included partying, lying and not reporting that your daughter was dead. >> reporter: perhaps even tougher for the defense, key word searches done on the anthony's computer, months before caylee died. >> searches of the words "inhalation," "chloroform" and "death." >> reporter: if casey's allegations of her father are true, it does not seem evident here. >> good morning. >> good morning, beautiful. >> i love you. >> i love you, too. >> reporter: and when george anthony sat down with abc news last year, just as casey's accusations were surfacing, he addressed them head on. it didn't change how you feel about casey? >> i'm still going to be there for my daughter.

that's unconditional love. it really is. >> reporter: and in court today, he was asked about all of it, as the prosecution's first witness. >> have you ever sexually molested your daughter casey anthony? >> no, sir. >> were you present in your home when caylee anthony died? >> no, when i heard that today it hurt really bad. >> reporter: still ahead, jurors will have to tackle cutting edge forensic science, like smell evidence, air samples taken from the trunk of casey's car. and then, of course, casey herself. will she take the stand and tell her story? or stay silent and hope for reasonable doubt? for "nightline," ashleigh banfield, abc news, orlando, florida. 10% of the world's medicine is counterfeit.

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supermodel petra nemcova lasted five weeks on this season's "dancing with the stars." you'll remember she sustained life-threatening injuries in the 2004 tsunami. but it turns out she more than got her own strength back. she has enough to go around. here's david muir. >> reporter: she is the supermodel stunner who dazzled on the dance floor, too, daring to go on "dancing with the stars" this season. but all the while, petra nemcova was carefully choreographing something else. from los angeles, she boarded a plane for haiti.

part of a journey that began for petra even before the devastating earthquake. we were on a plane from new york. >> how are you? thank you for coming. >> reporter: this country of survivors, petra is a survivor, too. december 2004, the tsunami in thailand. she and her fiance swept away by the waters, her pelvis crushed. she held onto a tree for her life, for eight hours. her fiance did not survive. nor did so many of the children dragged out by the water. you said you would never forget the voices of the children screaming out for help. >> yes. i was not able to help those children. you heard them screaming for help and after some time, you didn't hear their voices anymore. >> reporter: it was then petra decided she would build schools where disaster had stolen them from the children. she's now built 51 schools from you over the world. and on this day, her first one in haiti. how in kids are in the kinder

guarden? >> 102. >> reporter: and soon, on our ride, the first signs a child riding her bike in her school uniform. and then we see it. patiently waiting, the kindergarteners in their yellow checked shirts. inside the school, the first reading lessons. and petra told me that their laughter, their smiles, have helped heal her, too. >> when i first came to haiti, we saw children without hope and today, we see children with happiness in their eyes. >> reporter: you see the hope? >> i see the hope, i see the joy. >> reporter: before we left, a little girl staring into the eyes of that supermodel, known here simply as the woman who gave these children a school. i'm david muir for "nightline" in port you a prince. >> graceful in every way. and finally tonight, breaking news. abc news has learned that the u.s. department of justice has green-lighted the prosecution of former presidential candidate john edwards for alleged violation of campaign laws while seeking to cover up an