mr. trump blaming the crisis on the biden administration. our team on the border. also this evening, israeli troops accused of opening fire on a crowd waiting for aid in gaza and killing more than 100. israel disputing that, saying many were trampled while looting trucks. all as gaza reaches a grim milestone. an estimated 30,000 dead. the wildfire raging in texas, now the largest in state history. more than one million acres burned. we're in the fire zone. the life-threatening winter storms slamming the west coast. blizzard warnings in california for up to ten feet of snow. defense secretary lloyd austin on the hot seat. the heated moments as house republicans grilled him on his secret hospitalization. the cheaper choice when it comes to popular weight loss drugs, but what are the health risks? and our exclusive. nfl star damar hamlin after surviving that heart scare on the field. we're there as he surprises a teen athlete who shares a special bond. >> announcer: this is "nbc nightly news" with lester holt. >> good evening and welcome. the race for a president still officially in its primary season leapfrogged straight into the issue at the heart of the 2024 race. the two front-runners traveling to the southern border, making duelling appearances on what could be a defining battleground in this campaign. president biden and former president trump each standing in the shadow of mexico today, separated from each other by hundreds of miles, but exchanging salvos over an issue impacting more and more american cities on the border and beyond. the president calling out house republicans for sinking a bipartisan border bill and extending an offer to mr. trump saying we can do it together. the former president blaming mr. biden for border chaos, calling it a joe biden invasion. our gabe gutierrez has late details. >> reporter: facing criticism over his handling of the immigration crisis, president biden making his second trip to the southern border while in office. >> it's real simple. it's time to act. >> reporter: arriving in brownsville, texas, blasting house republicans for tanking a bipartisan border security bill at the urging of former president trump. >> it's the toughest set of border security reforms we've ever seen in this country. it's time for the speakers and some of my republican friends in congress who are blocking this bill to show a little spine. >> reporter: the president with this message directly for mr. trump. >> join me. or i'll join you in telling the congress to pass this bipartisan border security bill. we can do it together. >> reporter: earlier, the republican front-runner landed about 300 miles away in eagle pass, texas. >> this is a biden invasion over the past three years. >> reporter: arguing president biden could end the crisis on his own, slamming what he calls mr. biden's lax border policies for causing it. >> so we had remain in mexico. remember that? you can't come into our country. and we had no more catch and release. our catch and release, we released them in mexico. >> mr. trump pointing to recent high profile crimes allegedly committed by migrants, including the murder of georgia nursing student lakin riley. >> joe biden will never say lakin riley's name, but we will say it and we'll remember it. we're not going forget her. >> reporter: an nbc news review of available crime data shows crime has dipped in cities that received the most migrants. should president biden have gone to a different part of the border? >> i believe so. i think it probably would have been best to go that's very busy, like arizona or california. >> reporter: a record 8.6 million migrants have crossed into the u.s. since president biden took office. the border patrol union telling us mr. biden should not have reversed trump border policy. >> they were very effective for us as border patrol agents in securing the border. >> an nbc news poll shows 57% of americans say mr. trump can best secure the border. just 22% say biden will. beyond the political split screen, desperate migrants in mexico wait to cross. here in brownsville, monica from el salvador waits for a bus with her 3-year-old son. she tells us the journey was hard, and that she spent four months waiting in mexico for an appointment for an initial asylum screening through an app on her phone. now she is off to meet family in houston as the border battle in washington intensifies. and gabe, a win for the white house today in its legal battle with texas regarding the border? >> that's right, lester. today a federal judge temporarily blocked the controversial law in texas that would have allowed local police to arrest migrants suspected of being in the state illegally. the governor says he will appeal, and the case could eventually make its way to the u.s. supreme court. lester? >> all right, gabe gutierrez, thank you. a deadly incident today in northern gaza during a food distribution effort. but how it happened is in dispute tonight. this as the health ministry now puts the gaza death toll from the war at over 30,000. raf sanchez has late details. >> reporter: tonight, bodies carried away on donkey carts after a deadly encounter while palestinians gathered to receive humanitarian aid. but how it happens is in dispute. our camera crew was there before 4:00 a.m. as hundreds of people came to the gaza coast waiting desperately for the delivery of food. israel less military saying this drone footage was taken soon after, showing a crowd surging around aid trucks. a palestinian eyewitness tells nbc news israeli forces started firing at people gathering in front of a checkpoint before the trucks arrived and kept shooting later as the crowd rushed towards the aid. the hamas-run health ministry says more than 100 people were killed, hospitals flooded with gunshot victims. but israel's military saying many died, not from israeli bullets, but in a stampede around the trucks. and that israeli troops only opened fire later at a specific group threatening their position. do you have any evidence to support your claim that this crowd posed a threat to israeli troops? >> if you approach armed soldiers in a war zone and there is a threat and they fire warning shots in the air, the best thing to do is to turn around and walk away. >> reporter: and tonight the u.n. warning that one in four gazans are just a step away from famine. moussa is 6 months old, barely older than this war. but in his tiny body signs of a short life with little food. in a sense, he is lucky. doctors say eight other children died this week from malnutrition and dehydration, all at this one hospital. not far away, sami al masri trying to feed her kids by frying pancakes out of barley feed meant for donkeys. her children dodging bullets to find firewood. "words can't describe the tragedy we're living in," she says. and president biden now says he no longer thinks a ceasefire by monday is likely. lester? >> all right, raf, thank you. here at home, that massive and deadly wildfire in texas became the biggest fire in the state's history today, burning more than one million acres. our guad venegas is there. >> reporter: tonight, the texas panhandle engulfed in a deadly ring of fire. as firefighters race to beat back the flames of what is now the largest wildfire in the lone star state's history. the smokehouse is the biggest of four active wildfires ravaging the state. it's already burned through more than 4,000 acre, leaving apocalyptic scenes like this in its wake. entire neighborhoods leveled. for paul blankenship, home won't ever be the same. the flames took his mother, joyce. >> the flames already blocked the roads off. i wasn't able to get in there to her. >> reporter: the colossal blaze is just 3% contained. today a surreal scene fritsch, texas. freezing temperatures led to a snow flurry coating the ashes. it's a help to firefighters still extinguishing hot spots, but the weather may not stay helpful for long. >> it's basically a product of low relative humidity, dry fuel conditions, and really, really high winds. >> this was my art studio. >> reporter: it's already too late for melanie. her home is gone. now she is worried about the historic hotel she manages. >> i looked at my house. i said goodbye and thank you, because i knew that i was not going return. >> reporter: until the flames subside, the hotel is putting up fire crews and evacuees. for now the fire rages across these vast farm lands, scorching crops and forcing some farms to release their cattle to escape the blaze. >> it's really going to hurt, and all the ranchers around it, it's going to be devastating for our community. >> reporter: with more high winds forecast in the coming days, this battle is far from over. >> and guad, do firefighters have enough help or do they have to go outside to bring in more folks? >> well, lester, federal firefighters are on the way, and president biden says air tankers are also coming to texas to help fight this blaze. there has been a break in the wind conditions giving firefighters that edge. but forecasters say the heavy winds are expected to come back over the weekend. lester? >> all right, guad, thank you. and in northern california tonight, blizzard warnings are in effect for the sierra nevada mountains with heavy snow already creating chaos on some roads. 5 to 10 feet of snow possible by sunday, with wind gusts between 60 and 100 miles per hour. travel will be extremely dangerous, if not impossible. in alabama, state lawmakers passing new protections for ivf after that state's supreme court decision that found frozen embryos as children. sense shockwaves across the country. laura, this would only be a temporary fix if you with will? >> yes. lester, lawmakers today acknowledged these bills are not a long-term solution. instead, they're meant to shield ivf patients and doctors from civil suits during the course of treatments where embryos could be damaged or destroyed. the goal is to give clinics in the state enough comfort to resume ivf procedures that have been on hold for more than a week. but the bills do not clarify whether the frozen embryos should be considered children, the crux of the supreme court's ruling, potentially leaving a legal gray area. nevertheless, the governor is expected to sign the proposed legislation as soon as next week, lester. >> all right, thank you, laura. just in tonight, a major turn in the case of a national guardsman accused of leaking secrets. jack teixeira is expected to change his plea to guilty, according to court papers. teixeira, who was arrested last april is accused of using his top secret clearance to access classified material and then posting it in a chat forum. a combative hearing today in congress where defense secretary lloyd austin was questioned about his recent hospitalization and failure to disclose it to the president and others for days. courtney kube has more. >> reporter: defense secretary lloyd austin in the hot seat today. >> it was a failure of leadership. >> reporter: house republicans grilling austin for not telling the white house he was diagnosed with prostate cancer, underwent surgery for it, and weeks later was hospitalized with serious complications. >> i find it very concerning that the secretary could be hospitalized for three days without anyone else in the administration even noticing. >> either the president is that aloof, or you are irrelevant. which one is it, mr. secretary? >> it's neither. >> reporter: democrats were more forgiving. >> you want to know what accountability is? accountability is having to come and sit in front of people and their outrage and their drama. >> reporter: the secretary emphasizing that someone was always in control. >> there was never a laps in authorities or command and control. >> reporter: but acknowledging a breakdown in the notification process. >> we did not handle this right, and i did not handle it right. >> reporter: although austin took responsibility, he also said he assumed his staff would manage it. >> i never directed anyone to keep my hospitalization from the white house. >> reporter: on monday, the pentagon releasing a summary of a classified review that blamed the lack of notification in part on a lack of written guidance, but also on staff not wanting to pry into austin's health. the review recommending new procedures. if any american worker did what you did, why they would be fired. >> reporter: and the questions still remains. why did it take the pentagon three days to tell president biden his defense secretary was in intensive care? courtney kube, nbc news, the pentagon. with just one day to go, the house passed a stopgap funding bill today to avert a partial government shutdown. the bill keeps much of the government open through next friday, and the rest open until march 22nd. republicans and democrats are far apart on funding decisions for major departments like the pentagon and homeland security. in 60 seconds, with the new class of weight loss drugs soaring in popularity, not everyone can get them. and now more people are turning to an alternate option. but is it safe? we'll look at that, next. wanted a recliner. but it had to be chic. so we wayfair'd it. wayfair for the win. hey neighbor looking fancy. fancy? nah. we wayfair'd it and saved a ton. wayfair does it again. it's beautiful i didn't know you wayfair'd. oh girl we wayfair, tile, faucet... the works. guess the wayfair word is out! ♪ wayfair you've got just what i need ♪ i won't let me moderate to severe plaque psoriasis symptoms define me... emerge as you. with tremfya®, most people saw 90% clearer skin at 4 months... ...and the majority stayed clearer, at 5 years. serious allergic reactions may occur. tremfya® may increase your risk of infections and lower your ability to fight them. tell your doctor if you have an infection or symptoms or if you had a vaccine or plan to. emerge as you. emerge tremfyant®. ask you doctor about tremfya®. oprah winfrey anno oprah winfrey announced she is stepping down from the board of weight watchers after going public about using weight loss drugs. these medications are wildly popular, though the cost has led many to seek out cheaper compounded versions. but are they safe? cnbc's melissa lee reports. >> you want to keep the same length? >> reporter: for new jersey hairstylist kelly, maintaining a healthy weight was never an issue, until she had a child. >> had my son, and we all know after 30 things kind of start to change. >> reporter: she wanted to try ozempic, the diabetes medication that is also shown to be effective and popular for weight loss. >> but the reality was at $800 a month, it wasn't something that was sustainable for me. >> reporter: when there is a nationwide shortage for a drug like ozempic's active ingredient semaglutide, the fda allows for what's known as compounding, the art of mixing in medications. >> i'm on my way right now get my first shot. >> reporter: she was able to get her hands on compounded semaglutide, first from a local med spa for $300 a vial, then an online site. she loads the syringes herself. >> i was just told to sanitize the top of it each time. >> pull back a little bit. >> reporter: robin wagner is a professor at the uconn school of pharmacy and teaches proper compounding techniques. >> when there is a need and there is a profit, people will get involved in compounding. >> reporter: dozens of compounding pharmacies across the country are mixing their own versions of compounded semaglutide. and while some of the facilities are inspected by the fda, the drugs they make are not. the agency has issued warnings that compounded versions of semaglutide may carry more risk and negative side effects. >> the big issues with obtaining compounded semaglutide is i don't know where these molecules are coming from. i don't know how pure they are. what else is being added. >> reporter: social media sites like tiktok are flooded with influencers plugging promotions for various compound medications. >> discount code. >> you're going to use my code, lauren 50. >> reporter: our team wanted to see how easy it was to get compound semaglutide. we tried eight different telehealth sites that didn't require any blood work. using our real health information, we shouldn't have been approved, and all but two sites did turn us down. but with one, after a quick consult with doctors. i'm qualified. okay, five questions and that's it. great. >> this nausea kind of sucks. >> reporter: kelly has documented her experience on tiktok and is now sponsored by a telehealth company. she says she's comfortable with the choice she has made. >> i feel like when you feel like you have no other options, you jump for it and do what's necessary. >> reporter: for her, the reward outweighing the risk. for nbc news, melissa lee, new york. >> and for more, watch "big shot, the ozempic revolution" tonight at 10:00 p.m. eastern on cnbc. electric cars from china boom in popularity, the white house launches an investigation on whether they're compromising drivers' data. there they are! everybody get their banking done? 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(vo) ask your doctor about once-weekly mounjaro. finally, our "nightly news" exclusive. the nfl's damar hamlin and his surprise for a young athlete. priscilla thompson on the heartfelt connection they share. >> reporter: zeke menkins had big dreams of becoming a military pilot and playing football. but around sixth grade, that all changed. >> it hurt to breathe. it hurt to sleep. >> reporter: the cause, a leaky heart valve that would have to be replaced with a mechanical one. what went through your minds in that moment? >> i just kind of thought his world is going to come crashing down. >> reporter: on blood thinners for life, zeke's football dreams were over. when they told you you weren't going to be able to play football again, what was that like for you? >> probably one of the most devastating moments of my life. >> reporter: devastated, but not defeated, now 16, zeke is a track star with new passions like marching band and choir, and dreams of becoming an airline pilot. his story inspiring someone else. so how you feeling about this surprise? >> i'm feeling super excited. >> reporter: buffalo bills safety damar hamlin suffered cardiac arrest on the field last year. >> i'm super proud of him, of being able to shift gears and still, you know, display your passion for other things that you love in the world. >> where is zeke? >> reporter: hamlin inviting zeke to join abbott's heartmates team. >> you're first pick in the draft. here you go. >> reporter: for those impacted by heart conditions. >> it's just a community that we built to allow people to know that you're not alone. >> reporter: did you experience any of that loneliness or isolation? >> yeah. i still do. it's something ongoing. >> reporter: a life-long journey of healing hearts. priscilla thompson, nbc news, midlothian, texas. >> what a great moment. glad we could share it. that's "nightly news" for this thursday. thank you for watching. i'm lester holt. please take care of yourself and each other. good night. a warning to stay away from the sierra. a massive storm is moving in and it could make it unsafe for anyone trying to get up to the snow. good afternoon an