Intensifying missile attacks are pounding the gaza strip. Part of an escalating conflict that has the World Holding its breath, fearing a new war in the middle east could erupt at any moment. Tensions between the israelis and palestinians are threatening to boil over, in a region still destabilized from the arab spring. Abcs Christiane Amanpour reports from a middle east on the brink. Christiane . Reporter cynthia, tonight, i can tell, you jerusalem where i am is extremely tense. Here and around the world, everyone is watching to see who will make the next move in this increasingly deadly game of chess in the holy land. The last time there was this kind of violence was four years ago when israel conducted an air and Ground Invasion of gaza, it lasted three weeks and left more than 1,000 people dead. After days of tit for tat attacks between israelis and palestinians, the Israeli Military stepped up, launching what they call operation pillar of defense. Its first target was a military chief for hamas. The Islamic Political Party that governs the gaza strip, which israel and the west call a terrorist organization. The Israeli Defense forces proudly hailed his assassination, releasing this poster. But his death was just the beginning. Five of the palestinians killed so far were children, including this 11monthold baby, held in the arms of his father, a local journalist for the bbc, who asked, what did my son do to die like this . This morning, ah ha has leader vowed revenge, telling reporters, israel started this war, but they will never know its end. Our rockets will hit tel aviv. We have a plan in place and they will regret what they did. And hamas made good on that threat, launching a rocket attack on tel aviv, israels largest city, where residents crouched in fear. Tonight, israeli troops were seen making their way to the gaza border. A grim indication that a ground war may be next. This battle, which is playing out against the background of an impending election in israel, is the worst fighting the region has seen in years. The last time rockets threatened tel aviv was during the 1991 gulf war, when saddam husseins missiles hit the city. And tonight, tensions inside gaza remain high as my colleague, alex marquardt, found out. Reporter the cloud of an israeli missile strike met us as we arrived in gaza at sunset. It is eerily quiet here. This is definitely the quietest ive seen it. Very few people in the streets. All the homes and shops are closed up. Everyone seems to be hunkered down inside. For good reason. Israel so far has targeted 300 sites in gaza. Missiles rained down with loud thuds if theyre far away. Deafening booms if theyre close. This is what the aftermath of one of these strikes looks like. A massive crater filled with cinderblock and rebar, the strong smell of diesel fuel. Several of the houses around were damaged very badly. And the residents here on this street say they hope hamas will keep firing rockets into israel in retaliation. A crowd of men was gathered outside one of the houses. We met this 30yearold, who said the strike felt like an earthquake. Theyre targeting civilians and kinds, he calling on hamas and other groups to hit hard. Reporter back in washington, president obama has been making calls to the middle east. I want to express my thanks to president obama. Reporter here, in israel, the government has taken this battle to social media. Its official twitter field has blasted out threats to hamas. It warned yesterday that no hamas operatives, whether low level or senior leaders, show their faces above ground in the days ahead. Hamas fired back with this tweet, our blessed hands will reach your leader and soldiers wherever they are. You opened hell gaeflts on yourselves. Just days after winning reelection, the president is now faced with a widened conflict that has the potential to destabilize an already unstable region. I think the number one worry at the white house today was containment. They want to contain this crisis, because they can imagine scenarios where it gets much more out of control than it has already. Reporter this is the first israel Palestinian Conflict of the new middle east. The arab spring has raised all sorts of new questions for the united states. For instance, its friend egypt used to be able to keep the peace in this region. Will egypts new islamist president do the same . And, of course, the arab spring means the governments are much more answerable to their own people. Here in the region, everyone is hoping this is over quickly. No one can afford a wider war. Thank you, Christiane Amanpour reporting. As of tonight, the death toll stands at at least 19 palestinians dead and 3 israelis. Just ahead, were going to change gears to meet the parents and adopted children united in an unlikely place. Craigslist. Anncr some politicians seem to think medicare and. Social security are just numbers in a budget. Well, we worked hard for those benefits. We earned them. And if washington tries to cram decisions about the future. Of these programs into a last minute budget deal. Well all pay the price. Aarp is fighting to protect seniors with responsible. Solutions that strengthen medicare and. Social security for generations to come. We can do better than a last minute deal. That would hurt all of us. Ii invest in what i know. R. I turned 65 last week. Im getting married. Planning a life. There are risks, sure. But, theres no reward without it. I want to be prepared for the long haul. I see a world bursting with opportunities. India, china, brazil, ishares, smallcaps, largecaps, ishares. Industrials. Low cost. Every dollar counts. Ishares. Income. Dividends. Bonds. I like bonds. 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A place where people buy and sell their old stuff, that marketplace is now facilitating adoptions. Good idea . We asked abcs reena ninan to take a look. Reporter what youre about to see is a most unusual family reunion. Hi reporter 2yearold ben welcoming his biological mother into his home for the very first time. His adopted family right behind him. Hi reporter an extraordinary journey for all of them. Tammy, the girl from the wrong side of the tracks, who gave ben up. Tracy, the suburban mom who took him in. Perhaps most stunning, though, is how they found each other. What do you say when you tell people, i found my baby on craigslist . Yeah, well, i try to phrase it a little differently, but people do sort of give us a look. Like, on craigslist . Reporter yes, on craigslist. The worlds most famous online marketplace. The site where you can find anything. Even a child these days. Adoptive parents across the country are taking the controversial step of connecting direct it will with potential birth mothers. All with just the click of a button. Craigslist put the power back in parents and birth moms hands. Reporter yahoo reporter piper weiss has been investigating the world of private adoption online. But it also forces both of them to be their own filter and to be kind of their own expert in the matter and that takes a lot of theres a lot of risk and reward to that. Reporter megan and steve in buffalo new york learned it the hard way. After successfully adopting aiden, they wanted to give him a brother or a sister. So, they started advertising online. They were contacted by a woman claiming to be pregnant. I thought it was it was a little bit sketchy, because wed get a new phone call and it would be like, you know what, we really need that 50 for gas and by the way, im going to need that weekly. When somebody is pushing money, money, i need it yesterday, its instabtly a concern. Reporter megan and steves adoption coordinator googled the womans name, kimberly, only to discover she had been convicted of sending bad checks, Identity Theft and burglary. Reporte do you get discouraged . All the time. Theres great days and then theres not great days. And the thing that keeps you going is knowing that it had to happen. And it will. Reporter tracy and dan had the same optimism during their search for a child. They tried everything. They designed their own website. Even plastered their car with this ad. You dont wait for a job, you look for a job. Why would you wait for a baby . Reporter after spending so much time, energy and money, nothing seemed to work. They decided to try something different. Did you think its a little crazy, though . Im going to search for our future baby online on craigslist. Well, we met online. So, if i were going to look up a word in the dictionary, i wouldnt go to my bookshelf and open up my dictionary. You just turn to the internet. The second i read their ad, i called there. Hi, im pregnant. And i need help and she was like, were really happy you called. Reporter tammy nelson was stuck in a nightmare. Financially dependent on her abusive husband and already raising one son, rider. I remember one time, feeding my son the dust out of the rice krispie box. The last bowl of cereal we had and i didnt know where the next meal was going to come from. Reporter but her nightmare got worse when she says her husband forced her to get pregnant again. You hate yourself a lot for it, because you feel like you should just have a connection with something thats naturally inside you. I felt guilty that i never had that connection. Reporter for tammy, abortion wasnt an option. Giving up the child was the right and only thing to do. What do you think . Ten fingers, ten toes. Reporter what was it like the first time you went and saw ben . She wanted me in the room while he was born, so, they put him right in my arms, so reporter what was that like . Amazing. Reporter two years have passed. Tammy started rebuilding her life with a new partner, now fiance patrick. Boom reporter shes been watching ben grow up through facebook updates. It is hard seeing ben be able to do stuff that i was never able to afford for my first son. Reporter like what . Like gymnastics. I think every parent wants the best that they can do for their kid. Im happy that ben has it, but it also kind of shows my inadequacies with my own son. Reporter theres been very little direct contact. Shes seen ben only once since he was born. Hes so young. He doesnt really know whats going on. Just kind of an awkward situation, i guess, for everybody. Reporter this past week, tracy and dan invited tammy over for a long anticipated visit to their home. Is that theirs . This is the house. Oh, my gosh. Hi reporter the reunion is awkward. Ben is more interested in our cameras than his birth mom. Hey, ben. That. You like the right . Reporter but the awkwardness pales in comparison to the overwhelming feeling tracy and tammy both have. Gratitude. We just cant thank you enough for everything. Everything. Such a great experience and he is so fantastic. Youre everything i expected in a mom for ben and thank you. Reporter im reena ninan for nightline in minneapolis. And our thanks to reena ninan. A special thanks, too, to yahoo shine who partnered with us on this report. Now, just ahead, our team heads deep into the amazon jungle to help track down some of natures most terrifying beasts. [ male announcer ] how can power consumption in china, impact wool exports from new zealand, textile production in spain, and the use of medical technology in the u. S. . At t. Rowe price, we understand the connections of a complex, global economy. Its just one reason over 75 of our mutual funds beat their 10year lipper average. T. Rowe price. Invest with confidence. Request a prospectus or summary prospectus with investment information, risks, fees and expenses to read and consider carefully before investing. Theyre the stuff of horror movies and urban legend. The most terrifying creatures Mother Nature has to offer. And one adventurer has made them his lifes work. Heres abcs matt gutman. Reporter blood thirsty beasts that feed on human flesh. Aquatic assassins that drag swimmers to their deaths. Myths, you might say, but sometimes truth is stranger than fiction. Thats where richard comes in, the swash buckling filmmaker, survivalist and hair product pitchman. Okay, maybe not the last one, but he could be. Richard is the host of nat geos man versus monster. He travels the globe to unravel the mysteries behind the myths. Its a great reason to help find out the truth. To hear their stories and try to work out whats been frightening them. Reporter he will do whatever it takes to get to the bottom of these legends. And these adventures are very real and rough and ready. Reporter richard is going to show me what it takes to survive a night in the monster capital of the world. Amazon. Last year, he was here investigating a scaled creature that attacked this young boy, tiago. He was fishing using nets. He had a splash and he was cheque his net. As he was looking to see what it was, he was attacked from the water. Reporter he didnt see the animal, but whatever it was, it left its bite mark. An important clue, as richard began his investigation. I can see it in the net now. Reporter hes got his first suspect, the Worlds Largest fresh water fish, weighing in at 400 pounds. Could this be the culprit . Doesnt have a mouth big enough for the bite marks i saw. Reporter meanwhile, on our own monster quest, we find plenty. Although, admittedly of the miniature variety. Look at the side of that. Reporter my god. Which deliver whats said to be the worlds most painful insect bite. And fish catcher spiders. Theyre all over the place. Reporter but the worst, this cloud of unidentified flying bugs that seem to follow us everywhere. And especially my producer. Theyre in my esophagus somewhere. Reporter to survive, you need to eat, so, we head back to the water to catch our dinner. When suddenly, we notice red eyes glowing a few feet away. Before we know it, samuel has grabbed the little monster and hauled it back on the boat. Its a relative of the crocodile. Locals eat young animals like this one. Adults have been known to eat the locals. Look at the size of its head there. Its so distinctive, the black armor. This is a black cayman. This is a serious contender to be the creature thats been attacking people. Closest ive got yet but its just not long enough to match what people have been describing. Reporter richards search for the real monster will have to continue. But in the meantime, my attempt to survive a night in the jungle now hinges on samuels ability to catch our dinner. No. Reporter no, he didnt. Theres dinner. Oh. A monstans master monster hunte. Its time to leave the jungle life to the pros. You know when they say. When the going gets tough, the tough find the nearest barbecue joint. Im matt gutman for nightline in the a. M. Son. Thanks, matt. Man versus monster airs fridays. Finally tonight, a developing story in midland, texas. This evening, an 18wheeler parade float carrying wounded veterans was struck by an oncoming train, killing four and wounding 17. As of now, one person remains in critical condition. Gma will have the latest in the morning. Thank you for watching abc news. Coming up next on abc, abcs very own jake tapper on jimmy kimmel. Good night, america. Up next on an allnew Jimmy Kimmel Live that can help you lose your job, its called facebook