Defense. It wasnt much. One of the soldiers looked like he was barely into his teens. These are the Syrian Rebels the u. S. Is training and equipping. Until a few months ago, this whole area was controlled by isis. Gloomy days like these are a nightmare for rebel forces guarding the front lines. Isis militants use the fog as cover to launch sneak attacks. They cant see them coming until its too late to stop them. The group leader told us u. S. Warplanes cant see them, either. And while he said he was grateful for american support, he hadnt actually seen any of the u. S. Special forces now on the ground. But commander Lewland Rojava had. We met him at his base camp deep inside syria. What types of things are you discussing . Mainly coordination on the ground, he told us, weapons and ammunition and who gets them, and they also wanted to see how successful we are in fighting isis on the ground. We also asked villagers what they thought of u. S. Troops inside syria. If they bring peace and stability he said, theyre welcome. When you found out u. S. Troops were coming here, what did you think . 16yearold omar told us he was simply happy. The commander told us, scott, once u. S. Forces see for themselves what theyre up against, theyll realize they need things like Armored Vehicles and heavy weapons, in addition to guns and ammunition. He also said, depending on how things go, maybe america will send even more forces. Charlie dagata with a report from americas new battlefield in syria. Charlie, thank you. Now the u. S. Has also sent hundreds of troops to west africa, where islamic militants linked to isis are terrorizing villages in a campaign of murder and kidnapping. The americans are there to support cameroons army, and debora patta went along. Reporter cameroons elite counterterrorism soldiers gear up for the days patrol to the nigerian border. Balaclavas provide scant relief against the choking dust. Theyre searching for boko haram, the Extremist Group that has aligned itself with isis and killed more than 20,000 in the past six years. Border towns like kolofata have suffered a string of attacks by suicide bombers recently. Boko haram fighters frequently hide weapons and ammunitions in villages. Sniffer dogs look for explosives as soldiers go from hut to hut. The belief is boko haram could be in any of these homes and not even children are immune from security checks because in the past few months, the suicide bombs in this area have all been delivered by children. The new face of war. But today, they find nothing. Major beltus kwene tells the village to be vigilant. The soldiers base is just a few miles from the border. And youve been attacked here at this base. We underwent a massive attack at this base. Reporter kwene told us since boko haram has pledged allegiance to isis, their tactics have changed. Their bombs are more sophisticated and deployed with deadly frequency. When i see how horrible they can be, i think i will never, ever feel tired to fight against them. Reporter now cameroon is getting help from the u. S. Military that is setting up its first drone base in africa. Here, cameroon soldiers are learning how to use their own drones for surveillance. The u. S. Base wont be fully operational until next month. Captain Victor Guzman the United States forces is providing intelligence, surveillance, and reconnaissance assets to the Cameroon Forces to take the lead, fight the local threat, and not only is it local, but its grown to a global threat. Reporter the u. S. Will have as many as 300 troops on the ground in cameroon by the time its fully operational. Theyre also training the soldiers to prevent suicide attacks. Its critically important, scott, just 12 hours after we left kolofata, it was hit by a suicide bomber killing nine people. Debora patta, remarkable reporting from the heart of africa. Debora, thank you. An attempt to save coral reefs creates an underwater wasteland. Wasteland. And preserving movie classics oh no. under his breath hey man hey peter. unenthusiastic oh. Ha ha ha joanne . Is that you . Its me. You dont look a day over 70. Am i right . Jingle jingle. If youre peter pan, you stay young forever. Its what you do. If you want to save fifteen percent or more on car insurance, you switch to geico. You make me feel so young. Its what you do. You make me feel so spring has sprung. Weve been changing things up witoh yeah. Ve. Its a pleasure gel that magnifies both our sensations. It gives us chills in places weve never gotten chills before. Yeah, it makes us feel like. Dare to feel more with new ky love. Man mr. Mucus tore do you work, with you. Ing . Its taco tuesday. Man youre not coming. I took mucinex to help get rid of my mucusy congestion. Im good all day. [announcer ] mucinex keeps working. Not 4, not 6, but 12 hours. Lets end this an attempt to save florida coral is wrecking the reef instead. Apparently they didnt think through what sea water does to metal. Heres barry petersen. Reporter theyre off before dawn. Diver thomas pennypacker is on a rescue mission off the coast of ft. Lauderdale, saving a piece of floridas natural coral reef, from this, as massive 35acre graveyard of old tires. It started as a way to get rid of tires plugging up landfills back in 1970. Up to two million tires bundled by metal clips were dumped here to create an artificial reef. The hope was that they would spur coral growth and attract fish, all good for the environment. Really good idea . Really bad outcome. The clips rusted away. The tires broke free. Storms and constant ocean currents keep the tires moving, dragging across and damaging the fragile living reef nearby, says alex delgado, the dive coordinator. Right now, its just a wasteland. Its tires everywhere. And now we need to correct it before it does additional damage. Reporter down below here is the priority zone, where they had as many as 300,000 tires, but the tires have really spread throughout this area, all the way as far as the beaches of ft. Lauderdale. How you doing down there . Now, were in a pretty good spot. Reporter surrounded by a seemingly endless mound of tires, pennypacker slings them onto lines to be hauled up by a crane. Until he and his team fetch as many as 600 on a good day. Its a race against time. Pat quinn is the Natural Resources specialist for broward county. They wont break apart in our lifetime. Reporter so if you dont get them out of there, theyre just going to be there. Forever. Reporter so far, Florida State funding will bring the number of recovered tires to about 160,000. Not enough, say experts, to protect a reef 7,000 years in the making. Barry petersen, cbs news, off the coast of ft. Lauderdale. Still ahead, years after his death, Michael Jackson is still setting records. See you on the other side, ray. Nice working with you, dr. Venkman. Bill murray and dan aykroyd in ghostbusters, one of 20 classic movies added today at the film registry at the library of congress, films preserved due to their cultural importance. The list includes top gun, l. A. Confidential, and the Shawshank Redemption with tim robbins and morgan freeman. I guess it comes down to a simple choice, really. Get busy living. Or get busy dying. Fans of Michael Jackson got busy buying his 1982 masterpiece. Today, thriller became the first album to go platinum 30 times over. 30 million sold in the u. S. , more than a million since jackson died in 2009. Next, the new star at the national zoo. ,,,,,,,, the new baby at the national zoo, a baby pada, made its public debut today, so we sent cub reporter chip reid for a look. Reporter getting introduced to the media at four months old is something usually reserved for royalty. Well, thats exactly what bei bei is, the prince of cute. Millions of panda lovers have watched him grow up on the National Zoos pandacam, from birth when he was completely helpless to where he is today, which is just mostly helpless. Doctors say hes in Perfect Health and give much of the credit to mom, who endlessly plays with him, carries him over rocks, slides him across the floor, and nuzzles him to sleep. Brandie smith is in charge of animal care at the zoo. Right now, he is entirely dependent upon her, so hes not eating any solid food. Shes nursing him. Thats where he gets all of his nutrients. Everything comes from mom right now. Reporter today mom, or may shong, spent much of her time outside, leaving bei bei in the media glare with his keeper, juan roddriguez, known to bei beis adoring fans as the luckiest man in the world. Do a lot of people tell you, i want your job . Yeah, yeah. Pretty much every day. Being able to work with these guys, it just puts a smile on your face. I mean, you just cant get enough of it. Reporter the public will get to see bei bei in person starting next month. Today, after most of the media throng left, may shong finally returned and those remaining were treated to this the soft embrace of a mothers love. Chip reid, cbs news, washington. And thats the overnight news for this thursday. For some of you, the news continues. For others, check back with us just a little bit later for the morning news and, of course, cbs this morning. From the Broadcast Center in new york city, im scott pelley. Captions by vitac www. Vitac. Com this is the cbs overnight news. Is hi, everyone, and welcome to the overnight news. Public School Students in los angeles are back in class after the entire School System was shut down for a day because of a fake terror threat. The High School Kid also be wrapping up their finals with the holiday recess start thing weekend. And the threat of a Terror Strike took center stage in las vegas, and the gop president ial candidates squared off for their final debate of the year. Major garrett has the story. Reporter the debate was an instant capsule. A primetime event which the specter of terrorism and the nations fears about it overshadowed every other topic. In the end, offered an anxious nation a promise, one that could be distilled into one word, or phrase. We will keep america safe. Safe. Safe. Safe. Safe. Were talking about security. Reporter the competition to be tougher on National Security never ended, and jeb bush, running in low single digits, forced his way back into the conversation by repeatedly challenging donald trump. This is a tough business youre a tough guy, jeb. And we need to have a leader youre never going to be president of the United States by insulting your way. Lets see, im at 43 , youre at 3 . Reporter ted cruz and marco rubio clashed over National Security and border control. Cruz accused rubio for supporting a path to citizenship, branding it amnesty. Does ted cruz rule out legalizing people in this country now . Ive never supported legalization, and i do not intend to support legalization. Reporter calling the senators fights irrelevant, Chris Christie said his experience as a post 9 11 u. S. Attorney and new jersey governor makes him best prepared to be commander in chief. This is what its like to be on the floor of the United States senate. I mean, endless debates about how many angels on the head of a pin for people that have never had to make a consequence shall decision. I think when people discover he wants to get rid of the First Amendment to the constitution, they might say, oh, my god. Reporter we asked trump what he valued more, security or the bill of rights. Ive always come down on the side of security. Reporter even if it means doing something to encroach on the bill of rights . I hate it, i hate the concept of it, but we are dealing with some very bad dudes. Im committed to the republican party. I feel honored to be the frontrunner. Reporter trump senior advisers said trump had always been clear he would run as a republican, not consider a third party race. Trump made the announcement tonight that he now sees a clear path to the nomination. The city of flint, michigan is in a state of emergency. High levels of lead were found in the tap water. Adriana diaz has a report on how this crisis unfolded. Reporter when officials tapped into the flint river here for the citys drinking water, the strong chemicals corroded the pipes, contaminating the water with lead. By the time the city switched back to the original water source, families said the damage was already done. When i hear my son give up at night and cry because his bones hurt, and theres nothing i can give him, theres nothing i can do for him to take away his pain, i feel completely helpless. Reporter for nearly five months, melissa and her family drank the water, unaware there was lead in it. Maze says she noticed a change in her three children. Convulsions, skin lesions, memory and hair loss. My heartbreaks, because i handed them the water. Reporter last month, maze and other residents filed a class action lawsuit, accusing officials of not proper sampling the flint river water and delaying and notifying the publish of serious safety and health risks. They called the citys false denials about the safety of the water deadly and arrogant. They continually said the water is safe to drink. Reporter the water problems started in the spring of 2014 when flint moved its water supply to the flint river. It was supposed to save the city about 15 million a year. But the lead levels detected in flints children under the age of 5 nearly doubled, according to a study by a local center. In october, officials declared unfiltered water unsafe to drink. Shortly after, flint had to switch back to the detroit water supply. Flints new mayor, karen weaver, says the city needs to fix its decaying infrastructure. We made that switch to the flimt water, we damaged the flights. There was no Corrosion Control in place. Reporter the World Health Organization declares any lead in the body unsafe. And particularly toxic to young children. Severe cases of exposure may cause mental disabilities and behavior difficulties. Do you feel helpless in this situation . I can make nightmares go away. I cant fix this and i cant make this go away. Reporter the mayor says fixing the citys water system could cost 1 billion. She hopes declaring a state of emergency will unlock state and federal funding, but its not her call. The cash strapped state and federal government have to approve her request. President obama has been telling people to enjoy the holidays and not to worry about a possible terror attack. Experts say fear can have a real effect on your health, and our doctor, jon lapook, got the lowdown from justin sinclair. One of the things that is different about this, you know, this threat, is that, again, its ongoing. People cant know when and where or how its going to happen. Its this thing that never ends, its everywhere. Reporter how does that affect their lives . They tend to avoid different aspects of their lives. They fly less, they ride on Public Transportation less. They go into public settings less. Theres been research thats shown that they have a tendency to engage people from different cultural backgrounds less. They even consume media less, ironically. Reporter what have you learned over the last ten years of studying this that might surprise people . How potent fear can be in terms of altering peoples lives. And the impact that it can have in different aspects of life, whether its making decisions about a president , whether its supporting different policies that are important socially, or even down to sort of how people live their everyday lives. Reporter is there a danger of people in society changing their behavior because of terrorism . Yeah, it changes the structure of our country. It changes the structure of our government. Fear can maybe even change things in ways that werent consistent how the country was founded originally. Reporter as a psychologist, is there some insight into that . I think fear moves people to become much more polarized in their viewpoints, and i think fear motivates people to go to further lengths to feel safe. Olay regenerist renews from within, plumping surface cells for a dramatic transformation without the need for fillers your concert tee might show your age. Your skin never will. 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Well, the wait is nearly over for star wars fans. Its the first new star wars fill nm a decade and its got a new director, j. J. Abrams. As Bill Whitaker reports, abrams is under enormous pressure to make sure the movie hits all the right notes. Reporter six weeks before the premiere, we dropped in on a hollywood scoring session for the force awakens. The composer, who won an Academy Award for the first film, was back. Along with the iconic refrain he wrote 38 years ago. Take a look behind williams. Thats not some awestruck groupie. Thats the director, j. J. Abrams. I saw you up here with your video camera. This is momentous. John williams conducting his star wars music. As a fan, i cant believe i get to be here. Reporter abrams saw star wars when 4ehe was 11. On this day, he was racing around the sound stage. Its incredible. We may need to make the repeat those bars just because it might be a little longer before we get into the interior of the transport. Reporter i see you running around. Really . I felt so confident. Reporter this is you calm . Yeah. Reporter