tonight, travel at a standstill all along the east coast, flights grounded. a computer glitch bringing some of the nation's busiest airports to a halt. the cancellations, the delay, the headaches -- >> he said it was going to be an inde indefinite delay. >> felt all around the country. across the west, wildfires raging out of control. hundreds of families forced to evacuate. crews on the front lines racing to save their homes. politics, pork, yes, even a helicopter. the front-runners are at the iowa state fair tonight. we're there, too. the teenager trapped under his truck. he can't move, but he manages to enlist siri for help. >> send help, please! help me! >> now, that's a smartphone. and, the 70-year-old mystery. the kissing sailor and the nurse, who are they?

tonight, a new clue. it's great to have you with us on this saturday. i'm cecilia vega. we begin with a nightmare travel day for thousands of airline passengers. the affects of an air traffic computer failure rippling all across the country tonight. some are travelers stranded. here they are at washington's reagan national airport, waiting for the system to come back up. that airport, the hardest hit with cancellations and delays. this map showing just how bad it was at its peak. see that hole right there? empty skies from south carolina up through new york. abc's linzie janis starts us off from new york's laguardia airport. >> reporter: tonight, long lines and hours of waiting at airports across the country. hundreds of flights canceled and more than 2,000 delayed, with major east coast hubs hit the hardest. >> if you want to just shut them both down, you can shut them both down.

>> reporter: it all started around 11:30 a.m. and isn't over yet. the faa blaming an automation problem at its air traffic center in virginia. a computer system there responsible for processing flight data critical to air traffic controllers. >> they said the screens had gone blank and they were not able to, i guess, track the planes coming through that area. >> reporter: the result, chaos. airlines across the country forced to delay flights heading in and out of the northeast. in some airports, up to three hours. planes in the air diverted away from d.c. air space. that flight map showing no planes in the skies above d.c., virginia, maryland and north carolina. brian bartlett, trying to get back to d.c. after going to a graduation in denver. >> he said that it was going to be an indefinite delay. they wanted to de-board the plane. it would be at least 90 minutes before they even had another update. >> reporter: tonight, the faa assuring passengers the

technical problem was just that and not the result of a hack attack. but the incident comes just five weeks after a computer malfunction at united airlines triggered the delay of 800 flights. now, another summer trip interrupted for thousands more. cecilia, the faa tells us that system is now back up and running and it is trying to figure out what went wrong. the outage lasting five hours and, cecilia, the airlines now working hard to clear the backlog. >> a long day for so many people. linzie, thank you. we turn to the west now, and the raging battle against wildfires. 68 fires in seven western states burning out of control at this hour. this one right there in washington. tonight, the nation fighting more fires with more crews and more equipment than any time in the last 12 years. and with that comes the soaring cost, but now, federal money used in the night fight runs out in just a few weeks. abc's kayna whitworth is on the fire lines.

>> reporter: more than 13,000 firefighters battling 17 blazes across california. temperatures peaking at 106 degrees, sending some firefighters to the hospital with heat exhaustion friday. >> these firefighters, they've been doing this a long time, and they know they have to hydrate. but you know, those temperatures can creep up. >> reporter: the 2,800-acre cabin fire sending this plume high into the sky. the terrain described as the steepest in los angeles, making it hard to use engines. in simi valley, flames coming way too close. >> i got a call from my daughter and she was on her way home and she's crying and she goes, mom, it is our house. >> reporter: in washington state, you can hear the winds gusting up to 40 miles an hour. fanning the flames, thousands of acres burning, hundreds evacuated. >> i just hope and pray our house will be okay. >> reporter: hundreds more with no other option but to get out. >> i fought fire in the past, but it's different when your home and family and all your possessions are sitting in the way. >> reporter: a photographer from our seattle station right there.

watch as fire retardant is dropped right on top of him. this junkyard is consumed by fire. a race against time for so many rushing to clear brush around their homes. the drought-stricken west in dire straits. crews fighting the cabin fire are gathering water from this nearby reservoir. and can you s and you can see the plume of smoke behind me. that's where the fire is. this aerial attack is so important that they actually ordered nine air tankers, but with so many fires in the state and resources are stretched so thin, cecilia, they were only given two. >> kayna, thank you. rob is here now. the crews are really struggling out there. are they going to catch a break any time soon? >> reporter: well, they're going to see the winds diminish. not much in the way of dry lightning, but they're not going to get much in the way of rain. still very, very dry. residents are going to have to deal with air quality. very, very poor. highlighted yellow areas mean the smoke is just lingering. especially in the valleys. red flag warnings still up for parts of montana. and look at this dry air. the humidities in the single numbers during the day tomorrow for fresno and sacramento. and then of course, there's the heat, especially across the southwest.

heat warnings that are in effect at least through tomorrow, and in some cases through monday. phoenix, 115. that's likely to be another record tomorrow. palm springs, 118 degrees, cecilia. >> they could have another record, too. rob, thank you. and next, to that epic drought in california, may have played a role in the death of two young came persons in yosemite national park. a tree limb crashing down on their tent in the middle of the night. here's abc's aditi roy. >> reporter: officials at yosemite national park tonight are investigating what caused a tree limb to come crashing down on a tent with two young came persons sleeping inside, killing them both. >> i heard a woman screaming at the top of her lungs and i knew something was wrong. >> reporter: park rangers arriving at the campground to provide medical help -- >> the tree branch fell and struck them and, unfortunately, they died. >> reporter: the tragedy took place early friday morning. in one of the park's most popular campgrounds. just last month, a 70-foot tall pine tree fell on a group of

kids coming out of a children's museum in pasadena, california, injuring eight of them. experts say trees are especially susceptible, because of the state-wide drought and heat. the u.s. forest service says the drought has killed more than 12 million trees in california just this past year. it's still unclear whether this latest incident in yosemite is a result of the drought, but officials say that while the chances of being struck by a falling tree are pretty low, you should still be very careful of dry tree limbs. park officials in yosemite are still piecing together the latest tree collapse. a grim reminder of the unpredictability of nature. aditi roy, abc news, san jose, california. we turn next to a terrifying moment at the chicago air and water show today. two military parachutists apparently colliding midair during their performance. one jumper landing on the lakefront beach, the other crashing into a building. one of the men seriously injured. and to politics now, all

eyes on iowa this weekend. the state fair drawing presidential front runners for some politics and a lot of fried food. but one candidate coming in for a landing like no other. abc's devin dwyer is right there covering it all. >> reporter: donald trump arrived at the iowa state fair like a billionaire would. the only presidential candidate to arrive in a helicopter. a never before seen iowa attraction. >> who wants to go first? >> reporter: trump announcing free flights for kids as he promised to unveil new specifics tomorrow on his signature issue of immigration. >> you are going to love me in terms of immigration and illegal immigration. we're building a wall, it's going to be a wall that is not -- nobody's going through my wall, trump builds walls, i build walls. >> he's bold. speaks his mind. >> reporter: the republican front-runner's grand entrance captivating iowans. mobs flocking to the golf cart taking trump to the famous 600-pound butter cow. hillary clinton was also there, though she and trump never

crossed paths. >> how are you, bill? >> reporter: the democratic front-runner who lost iowa in 2008 back at it, doing what iowans do. petting the animals, sampling the pork. addressing, sort of, the controversy about an fbi investigation of her private e-mail server. >> this is the usual partisanization. which i may have just made up a word. >> reporter: what's the biggest mistake you think you've made so far in the campaign? >> i'm just having a good time. it's mostly, for me, a continuing conversation with the american people. >> reporter: today's enjoyment coming mostly in stick form. and amidst the hay beaalbales, e cattle are shown up and sized up just like the candidates. and trump and clinton spent an hour here at the fair, braving the crowds in a true presidential right of passage. cecilia? >> sure is. devin, thank you. and one of those getting a ride on trump's helicopter, our own martha raddatz. >> reporter: you don't think this is a little much? >> no. >> reporter: it's very trump, right? >> yeah, it's me. i am who i am. it's good for the kids, the kids

love it. >> you can watch martha's full behind the scenes report tomorrow morning on "this week." and we turn overseas now to china. that massive warehouse disaster growing tonight. new blasts and more evacuations in tianjin. authorities finding potentially deadly chemicals in the air there. this police officer wearing a gas mask to protect himself. the death toll now stands above 100 and is expected to rise. abc's bob woodruff reporting in once again from the scene. >> reporter: three days after those massive explosions, a miracle emerging from the charred rubble. rescuers pulling a 50-year-old man to safety. many of those rescuers wearing protective masks as they carry him to an ambulance. the man reportedly spent three days trapped in a shipping container, but tonight, he's recovering in a hospital. the race to find the missing, more urgent than ever, as explosions sparked new blazes. the government insisting the air

is safe. you can see that the police are clearing out the area. they have growing concerns. and now authorities have identified some of those dangerous chemicals unleashed by the disaster. one, sodium cyanide, could be deadly. relatives of missing firefighters stormed a news conference today, demanding answers. "we are extremely worried," this woman says. "our son, he's just turned 18." now, we've seen two mothers in extreme tears surrounded by friends, one of them was barely able to stand. cecilia? >> so many tough images out there. bob, thank you. and we turn next to the philippines. a double decker ferry with more than 500 passengers erupting into flames. this video capturing it all. some passengers jumping into the water to escape. remarkably, no passengers were hurt. and to cuba now. the american embassy back in business. the stars and stripes waving again after more than 50 years. and now, the question -- when will u.s. visitors follow?

abc's jim avila reports in from havana. >> reporter: american businesses streaming into havana airport, researching the market and potential. >> this sky's the limit. the cuban people are wonderful, so, i think it's a great opportunity. >> reporter: american tourism up an estimated 35% to 50%. the secretary of state, who toured old havana himself, encouraging americans to take advantage of the newly relaxed regulations that allow specific types of tourism. >> americans getting to know cubans and cubans getting to know americans is the way that, in fact, a transformation is going to be affected. >> reporter: this minnesota couple here in cuba, staying with airbnb, which now rents 2,000 rooms, helped by a hotel shortage and a rush of americans who want to experience cuba before it changes. >> a great time to come. it's a special time in history. >> reporter: do you feel like you're being watched? do you feel as though you are living in a communist or visiting a communist country

police state? >> no, i haven't noticed. >> not at all. >> reporter: cuba, defying the old cold war perceptions of secrecy and intrigue. jim avila, abc news, havana. and back here at home now with a new scam at the gas station. security cameras catching it all. a line of cars filling up, but the station's computer showing nothing going out. here's abc's ron claiborne with this high tech hacking. >> reporter: take a close look at this security video at a suburban chicago gas station. police say what this man's doing is selling gas that he's hi jacked from the station's bpump. he's filling up cars and pocketing the money while the cashier's computer inside shows nothing. >> i noticed that gas was being pumped, but nothing was indicating on the register. so, right away, my instincts kicked in that, okay, something's going on. >> reporter: it's a new and growing kind of theft. criminals hacking into gas pumps. >> there are several ways to do this. i believe the suspect in this

case may have used some type of remote device that would manipulate the components inside the gas pump. >> reporter: more often, criminals purchase a stolen master key to unlock the pump, open it and then enter the manufacturer's default code, which turns off the station's computerized system of monitoring sales. amazingly, those default codes can sometimes be found on the internet. >> punch in the manufacturer's passwords and chances are, you get a 50/50 chance that you're going to be able to override the electronic control system. >> reporter: it's a sophisticated and high tech way to steal gas, often without anyone at the gas station even being aware. some gas stations are now protecting themselves against hackers by resetting those codes that can so easily be found on the internet. cecilia? >> yet another thing to watch out for. ron, thank you. and we have much more ahead on "world news tonight." up next, you know the voice. >> my name is siri. >> yeah, siri helping one lucky man with a lot more than just directions.

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♪ sfx: crowd chanting sfx: crowd cheering music stops sc johnson, a family company. well, we've all been there, frustrated when siri doesn't understand what we are asking, but siri apparently heard one tennessee man loud and clear and tonight, he is thanking her for saving his life. abc's karen travers has the story. >> hello? rutherford county 911. >> help me! i'm stuck under my truck! i can't get to the phone. >> reporter: this frantic plea coming from a tennessee teenager trapped beneath his nearly 5,000-pound truck. >> send help, please! help me! >> reporter: 18-year-old sam ray was working on his vehicle when it slipped off this jack, pinning him down. his phone out of reach in his

back pocket, ray says he shifted his legs and hips and heard a familiar sound. it took a couple of tries, but ray managed to lean on his iphone, activating siri and asking her to call 911. >> help! >> we have everyone on the way. >> reporter: emergency responders rescuing a badly injured ray. four broken ribs, an elbow burned by the exhaust pipe, internal injuries. >> he probably crushed his kidney and so his kidney was torn and bruised. >> reporter: it's not the first time siri has been hailed a hero. this minnesota toddler knew how to use it to reach 911 when her mom had a medical emergency. sam ray says he wasn't a big siri user before, but recovering a month later from his injuries, he's calling her a life-saver. >> this is actually kind of a useful thing. >> reporter: karen travers, abc news, washington. >> bet he'll be using siri a lot more now. still ahead on "world news tonight," may the force really be with you. if you've ever wanted to pilot the millennium falcon, well, you might get your chance soon. i accept that i'm not 21.

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and to the index now. michael sam's pro football career may be over barely before it began. the first openly gay player drafted by the nfl announcing on twitter that he is leaving the sport over concerns about his mental health. sam had signed with the montreal alouettes but left training camp in june and sat out the team's first five games. next, using gaming to fight cravings? researchers say playing tetris for just three minutes can stop cravings for a number of vices, from drinking to drugs. the researchers say the game distracts the mind from thinking about over indulgences.

next, indulging all "star wars" fans. you won't have to go to a galaxy far, far away to get your fix. our parent company disney announcing plans for "star wars"-themed lands at disney world and disney land. think a millennium falcon ride. opening day, disney says it is coming soon. and when we come back, you know the kiss. but did you know that no one really knows who these lovers are? well, tonight, one step closer to solving that mystery. it's a highly thercontagious disease.here. it can be especially serious- even fatal to infants. unfortunately, many people who spread it may not know they have it. it's called whooping cough. and the cdc recommends everyone, including those around babies, make sure their whooping cough vaccination is up to date. understand the danger your new grandchild faces. talk to your doctor or pharmacist about you and your family getting a whooping cough vaccination today.

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>> two, one -- >> reporter: the countdown to a flashback in new york's times square. and there it is. kiss. smooch. smackeroo. all of it in tribute to this -- the famous "life magazine" photo snapped on the day world war ii ended. a sailor and nurse in celebration. who then, well, disappeared into the crowd so excited that day, their identities unknown. well, over seven decades, at least ten men have stepped forward claiming to be the kisser. a book has been written about it. and science has pushed the conversation a few different ways. there's this guy, for example, glenn mcduffie, who told diane sawyer he was emerging from the subway when he ran into a nurse he didn't know, edith shain, who told he the war was over. and -- bing. >> and it was a great kiss? >> it -- it was a great -- it was a good kiss. >> reporter: mcduffie's claim was backed up by a forensic artist. >> the hairline is the same right here. >> reporter: but there was also

this guy, george mendonsa, who says he was at a movie with his future wife, but ran out to the street around 2:00 in the afternoon when he heard the war was over and found the nurse to kiss. >> i looked at the features and i said, "that is me." >> reporter: mendonsa even had a computer take his face back in time to prove his point. the problem with his claim, physicists have recently analyzed the shadows in the photo, and they place the kiss at 5:51 p.m., almost four hours after mendonsa said it happened. well, whoever you are, or were, you could have just turned your faces ever so slightly in our direction and there'd be no mystery. but then, you were having a moment -- and that moment lives on. and on. and on. john donvan, abc news. >> it sure does. thank you for watching tonight. "gma" and "this week" in the morning. we will see you right back here tomorrow night. i'm cecilia vega in new york. have a great saturday. good night.

>> i'm karen rogers. >> and i'm erin o'hearn. saturday/tonight on fyi philly. >> it's philadelphia magazine's annual best of philly issue. >> and we're celebrating the winners! >> from best sandwiches, sweet treats and cocktails. >> to best beauty, fashion, fitness and fun! >> it's time to make that bucket list! >> hi everybody and welcome to fyi philly. >> we are on the battleship new jersey. philadelphia magazine's pick for best museum tour you haven't taken. >> and, if you really haven't, you really should because she is really a beauty. >> in the next half hour, we're going to meet as many best of philly winners as we can squeeze in! >> so let's get started with some of the best restaurant options. >> helm on north 5th street in kensington earned best new