styles, and invitations to the world's trendiest parties. but first here are the "nightline" 5. ne" 5. and number 1 is coming up in hiiiiiii! hey hun. look at all this extra room i have on this king size ikea bed. i'm rolling! are you wearing a... duvet cover? why yes. yes i am. looks good, doesn't it? (phone buzzes) you can't see me can you? nope. it's because of these new blackout curtains! hi kids!! where's mom? we finally redid our bedroom and she's prettttttttttty into it. what's your dream? at ikea, we help you live it. make the dream yours. good evening. in a country that is all too familiar with school shootings, tonight we witnessed something exceedingly rare. a massacre that simply will not recede from the headlines. today the gun debate provoked by the parkland school shooting only escalated, with more companies boycotting the nra and the president claiming he would have rushed into that building unarmed. here's abc's david wright in our series "the american gun." >> reporter: for students and teachers returning this week to stoneman douglas high school -- >> coming back to where everything occurred. it's just scary. >> reporter: there's no such thing as getting back to normal. not after the massacre that left 17 members of their community dead. >> we're almost there. >> reporter: this weekend an orientation for returning students. their first moments back on campus sunday felt haunted. >> i cannot stop looking at that building. i cannot stop imagining what was going on inside that building. it tears me up inside. >> reporter: the grief and horror are still fresh in parkland, as they once were in columbine and newtown and so many other communities. so many shootings, so little change. is it naive to hope this might be the "me too" moment for gun violence? >> we'll turn our grief into action. we have to have action. >> reporter: at the white house today president trump met with members of the national governors association. the president imagining himself as the hero. >> i really believe i'd run in there even if i didn't have a weapon. and i think most of the people in this room would have done that too. >> reporter: of course the school resources officer who was there and who did have a weapon did not go in. the president's called him a coward. today scot peterson, who resigned last week, responded with his side of the story. in a statement from his lawyer he claimed that he and the school security officer ran outside to respond to reports of a firecracker near the building. once there they heard gunshots but believed that those gunshots were originating from outside of any of the buildings on the school campus. after that the statement says peterson did what he was trained to do, taking up a tactical position nearby and coordinating with law enforcement as they arrived. "let there be no mistake, mr. peterson wishes he could have prevented the untimely passion of the 17 victims on that day, and his heart goes out to the families of the victims in their time of need. however, the allegations that mr. peterson was a coward and that his performance under the circumstances failed to meet the standards of police officers are patently untrue." schools across the country are reviewing their own safety procedures in the wake of parkland. today "nightline" was outside st. louis, where the o'fallon police department has set up a special training room to drill for active shooters. >> show me your hands! >> you get that adrenaline dump in this because it's as real as it can get. >> this scenario was a response to an active shooter in a school. we methodically went through the school. we were taking out suspects as we went until eventually we ended up with a hostage situation at the end. >> put the gun down! >> he was shot, and as he was shot he also shot the hostage. >> reporter: the authorities here designed this simulation with the company vertra. >> show me your hands. >> reporter: they've made modifications after what happened in parkland. >> it's horrible timing but it was good timing to do this. because everybody, all police officers right now and law enforcement is in that mindset of training for an active shooter. >> let me see your hands. >> reporter: in this simulation they're able to put an active shooter virtually on the steps of a local high school. this is modeled on real local schools that have never had an active shooter. and this principal hopes they never do. >> to see bodies down in front of my building, to see police officers actively firing on someone at my school, that's -- you want to think that could never happen here. but i'm sure that parkland felt the same way. >> reporter: the officers wear electronic shockers. if they're hit by gunfire, the shocker goes off. >> i was shocked by this. and it hurts. it definitely makes you realize that -- it makes the situation even more real. >> reporter: the challenge for the officers, to disable the shooter and stay alert. >> are you good? >> i'm good. >> reporter: most active shooters are lone gunmen. but not always. >> where's he at? >> reporter: it's a video game, but the pressure is real. >> get on the ground. >> reporter: turning every school into a possible s.w.a.t. scenario may be a necessary response, but it doesn't change the threat. that's the bigger fight. >> down on the ground now! >> reporter: speaking today to the governors, the president acknowledged that change will take courage. >> don't worry about the nra. they're on our side. you guys, half of you are so afraid of the nra. there's nothing to be afraid of. >> reporter: his ideas include banning so-called bump stocks, the accessory that the las vegas shooter used to modify his semi-automatic rifles to such deadly effect. trump insists he can get rid of them even without a bill from congress. >> bump stocks, we're writing that out. i'm writing that out myself. >> reporter: but the bureau of alcohol, tobacco, and firearms doesn't have the authority to ban bump stocks. and it's not clear that congress will act because so many lawmakers are afraid of crossing the gun lobby. >> what gun owners understand is that we're in this fight for the long haul. >> reporter: richard feldman is a former lobbyist with the nra. he insists the nra isn't the bad guy. >> we all want to keep guns out of the same hands. why don't we actually move forward in this country and do some things that we can agree on? >> reporter: president trump has also said he'd like to raise the federal minimum age for buying ar-style rifles from 18 to 21. but the nra has pushed back hard. >> the 5 million members of the nra have made their position incredibly clear. and i do want to caution people -- >> reporter: today the white house signaled that might be enough to make the president back down. >> in concept the president still supports it. but in terms of legislation we'd need to see what that looks like before we weigh in further. >> reporter: about the only idea from the president that seems to be a hit with the gun lobby is his proposal to arm teachers. >> i think it would be very effective. >> reporter: trump insists he's not talking about arming every teacher. >> i want highly trained people that have a natural talent, like hitting a baseball or hitting a golf ball. these are really gun-adept people. very few people would qualify. on top of being gun adept they have to go to school and they have to learn and maybe there will be a bonus given to those people. >> reporter: the democratic governor of washington state, jay inslee, rose to confront trump. >> i've listened to the first grade teachers that don't want to be pistol-packing first grade teachers. we need to listen, that educators should educate and they should not be foisted upon this responsibility of packing heat in first-grade classes. so i just suggest we need a little less tweeting here, a little more listening. >> reporter: a lot of americans seem to be uncomfortable with the idea of arming teachers, including quite possibly the president's own daughter. >> to be honest, i don't know. i think that having a teacher who is armed, who cares deeply about her students or his students and who is capable and qualified to bear arms is not a bad idea but it's an idea that needs to be discussed. >> reporter: what's especially interesting in the aftermath of parkland is the pressure being brought to bear by a new generation of activists. that activism is now raising the stakes, turning the nra into a corporate pariah. in the past few days nearly 20 companies have ended their nra discounts and partnerships. the challenge now for the activists is ratcheting up the pressure on the lawmakers the nra relies on to do its bidding. >> if the national rifle association's membership dropped precipitously, yes, they would lose some clout. but i certainly don't see that happening. >> now that you've had an entire generation of kids growing up around mass shootings and the fact that they're able -- they're starting to be able to vote explains how we're going to have this change. kids are not going to accept this. >> reporter: of course no one can bring back the 17 souls who died at stoneman douglas high school. but we can all work harder to make sure they didn't die in vain. i'm david wright for "nightline" in new york. >> and our thanks to david wright for his reporting tonight. next here, we switch gears entirely with our series "social stars." she even makes money by drinking water. how this instagram influencer turned her everyday life into a popular brand. not all fish oil supplements provide the same omega-3 power. introducing megared advanced triple absorption it supports your heart, joints, brain, and eyes. and is absorbed by your body three times better. so one megared has more omega-3 power than three standard fish oil pills. megared advanced triple absorption. thisat red lobsterest. with exciting new dishes like dueling lobster tails and lobster truffle mac & cheese. classics like lobster lover's dream are here too. so enjoy these 10 lobsterlicious dishes while you can because lobsterfest won't last. to everyone else, ieveryone else. but on the inside, i feel chronic, widespread pain. fibromyalgia may be invisible to others, but my pain is real. fibromyalgia is thought to be caused by overactive nerves. lyrica is believed to calm these nerves. i'm glad my doctor prescribed lyrica. for some, lyrica delivers effective relief for moderate to even severe fibromyalgia pain. and improves function. lyrica may cause serious allergic reactions, suicidal thoughts or actions. tell your doctor right away if you have these, new or worse depression, unusual changes in mood or behavior, swelling, trouble breathing, rash, hives, blisters, muscle pain with fever, tired feeling, or blurry vision. common side effects: dizziness, sleepiness, weight gain, swelling of hands, legs and feet. don't drink alcohol while taking lyrica. don't drive or use machinery until you know how lyrica affects you. those who've had a drug or alcohol problem may be more likely to misuse lyrica. with less pain, i can do more with my family talk to your doctor today. see if lyrica can help. powerful skincare,s now light-as-air a breakthrough moisturizer whipped for instant absorption feel a light-as-air finish in a flash new olay whips ageless [thinking] mexican spices? ♪ [thinking] nacho cheese sauce? they don't want these coming out. who's they? the burger people. they! they! nacho fries, now serving at a taco bell near you. [bong!] now to the of the young woman who gets paid seven figures just for using instagram. and her posts may influence what you wear. so what's her secret? here's abc's linzie janis with our series "social stars." >> reporter: front row seats at fashion week are usually reserved for magazine editors and movie stars. but the new it girls of fashion are instagram influencers. think of them as the reality tv stars. social media generation. >> they put us in a spot that was at the end of the runway so we could get a great shot of the girls walk in. also a very visible spot for other photographers. because we were all just in the collection. >> reporter: designers hand them up to tens of thousands of dollars for a single post. the influencer market now worth an estimated $2 billion and expected to reach 10 billion by 2020. >> this is what fashion week looks like in my living room. >> reporter: danielle bernstein has nearly 1.8 million instagram followers. >> i like to think of myself as a perfect mix of relatable and aspirational. i do that with my dressing as well. so not everything is high-end and designer. a lot of it is very affordable too. >> reporter: at 25 years old she's already made "forbes's" 30 under 30 list. her brand, we wore what, includes a blog, a podcast, a youtube channel, brand collaborations, and her own clothing line. earning her upward of seven figures a year. >> so we turned the second bedroom in this apartment into my closet. i needed the space. these are my overalls. >> these are the overalls you that designed. >> i designed. >> the leather pants. >> do you pinch yourself? can you believe you do this for a living? >> my mom always like literally gives me a pinch and she goes just remind yourself this is not real life. there is a really glamorous side to it. but i really do work hard. i get invited to a show, i'll usually be dressed by the designer. >> my front row babe. >> and then i'll sit front row and i'll be documenting the clothes as they come by so you really feel like you're there. it's really just a way to make fashion and fashion week attainable to the masses. >> good morning. >> reporter: danielle posts snippets of her daily life almost constantly. >> i actually think less than i would say the average person about what i post because it's so authentic and in real time. >> mommy's first fashion show. we're going to sally lapointe. both wearing sally lapointe. >> i just try to keep it real. i mean, i'm a young new yorker trying to make it like everyone else. >> reporter: she dropped out of college to pursue building her brand. >> and i was blogging more than i was paying attention in class. i was like, okay, i need to try to make this a real business. so i took two semesters off from school, and i blogged, and then i went back. >> reporter: her schedule today includes several outfit changes. five fashion shows. plus dinners and afterparty. >> we are on our way to one of my favorite shows every season, the zimmerman show. >> reporter: it's one of the season's hottest brands. >> the runway's absolutely stunning. it's like wallpaper everywhere. >> reporter: with pieces retailing in the thousands. throughout the show bernstein's followers are living vicariously through her instastories. >> after the show ends i quickly decide which ones are my favorite and i post those. >> reporter: back at the apartment she has 15 minutes to change. post again. and head to the next show. designer zadig and voltaire. another fashion photo op. today she even has her own camera crew documenting her as she documents herself. >> three of new york fashion week. >> although she wasn't paid to attend these fashion shows, many of her posts are paid advertisements. from these pony red kicks color coordinated with new york city graffiti to this h & m swag, these pretty petals from pro flowers, or this fiji bottle strategically positioned he next to her perfect pout, she's even making money drinking water. >> do you pay for anything? >> i do. yeah, i like to pay for things. but there's a lot that i don't have to pay for. i mean, all like the travel and beauty and all that kind of stuff is usually taken care of. >> reporter: she says she can have up to 20 different offers in a month. >> i've turned down jobs all the time. i won't put my name on something that i don't fully approve of. so when i have those design collaborations i'm at every design meeting, everything from the buttons to the stitching to the color to the way that it fits. >> and do you make a percentage on each item that's sold? >> so there will either be an up-front design fee and that includes for marketing and social media posts and all that kind of stuff, and then a percentage on the back end. >> what's the percentage on the back end? >> it varies. usually i like it to be half. >> reporter: influencer advertising is changing the fashion industry. now advertisers are thinking entirely differently about how they're spending that money. they're recognizing that there's this appeal with influencers like the post popular kid in class. >> so you decided to be transparent about how you make money. and that built your following. that helped build it up. >> yeah. it's weird when you say it like that because you know, hashtag ad and hashtag sponsored it doesn't look nice and it doesn't sound pretty, but being real to my followers i think actually helped me. >> reporter: being real is also the law. last year the federal trade commission stepped in to control transparency, reminding social influencers they're required to disclose paid posts. another issue is this burgeoning industry is grappling with, fake followers. >> advertisers are going to be take a closer look at this going forward because they really want that true value, that real relationship and that real following of true devotees, not bots. >> reporter: danielle says her following is real. and loyal. >> what's the goal? >> i get asked a lot what's your five-year plan? it's really just to grow my current businesses, invest and take part in new ones, and to just be a boss. >> reporter: for "nightline" i'm linz yooie janis in new york. next here, a math teacher going viral with shirtless workout videos. you're a life of unpredictable symptoms. crohn's, you've tried to own us. but now it's our turn to take control with stelara® stelara® works differently for adults with moderately to severely active crohn's disease. studies showed relief and remission, with dosing every 8 weeks. stelara® may lower the ability of your immune system to fight infections and may increase your risk of infections and cancer. some serious infections require hospitalization. before treatment, get tested for tuberculosis. before or during treatment, always tell your doctor if you think you have an infection or have flu-like symptoms or sores, have had cancer, or develop any new skin growths, or if anyone in your house needs or recently had a vaccine. alert your doctor of new or worsening problems, including headaches, seizures, confusion, and vision problems. these may be signs of a rare, potentially fatal brain condition. some serious allergic reactions can occur. do not take stelara® if you are allergic to any of its ingredients. we're fed up with your unpredictability. remission can start with stelara®. talk to your doctor today. janssen wants to help you explore cost support options for stelara®. but their nutritional needs remain instinctual. that's why there's purina one true instinct. real meat #1. a different breed of natural nutrition. purina one true instinct. now, try new purina one true instinct treats. this is charlie not coughing because he took delsym. this is charlie not coughing while not to waking zeus. and this is charlie not coughing while getting really into nana's party. nothing lasts longer than delsym for powerful cough relief. hiiiiiii! hey hun. look at all this extra room i have on this king size ikea bed. i'm rolling! are you wearing a... duvet cover? why yes. yes i am. looks good, doesn't it? (phone buzzes) you can't see me can you? nope. it's because of these new blackout curtains! hi kids!! where's mom? we finally redid our bedroom and she's prettttttttttty into it. what's your dream? at ikea, we help you live it. make the dream yours. and finally tonight, he's been called the world's sexiest math teacher. here's abc's kendis gibson. >> reporter: for millions of people around the world 29-year-old pietro boselli needs no introduction. >> i am a model with an academia background, funny enough. i have a ph.d. in engineering p p. >> reporter: boselli has been capturing the hearts of men and women ever since he became a viral sensation three years ago as the so-called sexiest math teacher in the world. >> the first few times i didn't realize i was thinking oh, my god, they're taking pictures of the notes, you know, i'm such a good lecturer. >> reporter: pietro has a history of modeling professionally but he put that career on hold to pursue another in math and engineering. >> learning's always been what has driven me. >> reporter: but after going viral, the only math people wanted to know was -- >> how many abs do you have? >> people say six. it's not really. it's only one piece actually. >> it's all one piece. >> yeah, it's all one piece. >> reporter: some of his most popular posts are of his workouts. so we decided to hit the gym. >> see? >> good effort, i think. >> when i'm sleeping, i skip. >> two more. >> what are you doing? >> i mean i have two more pancakes for you. >> reporter: for "nightline" i'm kendis gibson in new york. >> our thanks to kendis for that report, and our thanks to you for watching "nightline" tonight. as always, we're online 24/7 on our "nightline" facebook page. thanks again for watching, and good night. ♪ strummed guitar you can't experience the canadian rockies through a screen. you have to be here, with us. ♪ upbeat music travel through this natural wonder and get a glimpse of amazing, with a glass of wine in one hand, and a camera in the other, aboard rocky mountaineer. canada's rocky mountains await.