good evening. there are new developments in the flu epidemic now gripping the country. starting here in the state of new york, we're in the face of more than 19,000 reported cases of flu. the governor today declared a public health emergency. with the season not even half over, new york has already seen four times more flu cases than last year. in boston, officials report a tenfold increase in the number of cases. across the country, the latest tally shows the flu is now widespread in 47 states. we have two reports tonight on the impact and the effort to stop the epidemic in its tracks starting with nbc's gabe gutierrez inside an emergency room in brooklyn. gabe? >> reporter: good evening, lester. this is now the worst flu season here in new york since 2009. more than 19,000 reported cases so far. and because of that escalation, today the governor decided to

make the flu vaccine more accessible to children. for at least the next 30 days, pharmacists, not just doctors and nurses in new york state, will be allowed to give flu shots to patients older than 6 months. before they could only vaccinate adults. the governor's order comes after the death of 20 children across the country, since its flu season began a month earlier than usual. at the medical center er in brooklyn, one in three kids has been showing up with flu-like symptoms. this morning, it was the last place young mom ashley carasquillo wanted to be. >> i'm sick of the flu. >> reporter: she first got sick three weeks ago and then her 8-year-old aaron and now her 2-year-old chloe. as a mom, what is the toughest part about seeing your kids sick for so long? >> i can't say in words how tough it is. i cannot help my children the

way i want to. it is out of my hands. >> reporter: 47 states are reporting widespread flu. pennsylvania, one hospital has so many patients, doctors are treating them in tents outside. in boston today, more than 20 community centers opened as free clinics after the mayor declared a public health emergency this week. the city is dealing with a flu season that is so far ten times worse than last year's. >> in two hours we have given 400 flu shots. >> reporter: in several states in the west, health officials are bracing for a potentially rough week ahead. so far california has missed the brunt of the epidemic. yet some pharmacies are already running out of vaccines. >> with the flu vaccine, there is an extreme shortage. we're lucky to get it on a day to day basis. >> reporter: there are signs of some relief in parts of the south where the outbreak may have peaked. still, doctors aren't sure. >> we're hopeful those are early signs of declining influenza

activity in parts of the country. >> reporter: in brooklyn, ashley's daughter was able to go home today with a prescription for medicine and rest. a family, like so many others, sick of being sick. and despite spotty shortages in some parts of the country, the cdc says that there are plenty of vaccines to go around for now. lester? >> gabe gutierrez tonight, thanks. our chief medical editor dr. nancy snyderman joins me now from university medical center of princeton in new jersey. nancy, good evening to you. i have to think we keep hearing about the reported cases. i think of how many people are sitting home suffering, not going to doctors or hospitals. are these numbers really just a potential tip of the iceberg here? >> reporter: i think you're looking at two things, these numbers. one, this is not a reportable disease like so many other illnesses like meningitis or hiv. so right now i think we're looking at the federal government having a very different set of numbers and perhaps the hospitals and states that are on the front lines.

so we know we have at least 20 pediatric deaths across the country. but you're right when you talk about the people at home suffering, those who see their doctors, those who have been admitted, that's a bigger pool. for those states that have been hit with the cold wave, that nor'easter, two weeks ago, we're now seeing the upspike and that explains for boston having declared an emergency earlier this week and now in new york. >> and we're going to talk in just a second here about the strange weather we're having. how does that affect the number of cases we're seeing in places where it is unusually cold, more cases? >> reporter: yes, because when it is unusually cold, people are going to go inside and as they go inside, they spread this virus very, very efficiently. if you don't cover your mouth, this virus can jump six feet into the air, it can land on an inanimate surface and stay there for up to 24 hours. hand washing is of paramount importance. the flu vaccine is a 62% match, lower than some people would think. i would -- some people would hope, but i want to underscore

that means two out of three chance of in fact having fewer symptoms, decreasing your chances of getting in the icu and frankly surviving. so not too late to get your flu vaccine, especially if this goes into spring. >> dr. nancy snyderman, thanks to you. for more on how to protect yourself against the flu, go to our website, nbcnightlynews.com. as i mentioned, this was another day of highly unusual weather in much of the country. cold where it is normally warm this time of year and warm where it is supposed to be cold. nbc's kristen dahlgren has that story. >> reporter: tonight, arizona is facing its coldest nighttime temperatures in years. >> anything that is tropical is going to need to be covered. >> reporter: threatening crops and potentially skyrocketing produce prices. in california, major freeway i-5 had to be closed due to ice and snow for the second time in three days. temperatures in san diego, los angeles and san francisco will bottom out in the 30s tonight. >> very strong dip in the jet

stream has placed itself over the western part of the country and that's allowed some very cold air from canada to move southward. >> reporter: snow in new mexico made it look more like new york. that is if new york wasn't close to 50 today. in the east, many places were near record highs. in d.c. it was warm enough for shirtless beach volleyball. orlando was extra hot, even by florida standards. talk about upside down weather. on sunday, highs will be 57 in san diego, and one degree warmer in philadelphia. and flagstaff, arizona, will be exactly the same temperature as green bay, wisconsin. just 21 degrees. forecasters say more seasonal weather should return next week. already snow is being measured in feet in parts of utah. while the system that brought blizzard conditions to the dakotas is now headed east. kristen dahlgren, nbc news, los angeles. we're not only seeing unusual weather, but some severe

weather across the country too. in livingston county, kentucky, a possible tornado leveled a church and brought severe thunderstorms to the area. dr. greg forbes is the weather channel's severe weather expert. dr. forbes, good evening. >> reporter: good evening, lester. and that particular tornado is in the southwest flow, this very warm air that is in the jet stream coming northbound. we have the jet stream goes way southbound and the western parts of the country, so in that dip there, it is very cold, but that pattern is going to continue. we'll have some of this warm air across the east and southeast. in the midweek, the cold air ever so slowly beginning to work its way to the northern parts of the country. the following week, finally beginning to see a cooldown for parts of the northeast and the southwest parts of the country will begin to warm up. so we're in a bit of a roller coaster pattern in terms of the temperatures and the weather for mid-january. lester? >> dr. greg forbes, thanks. nice to have you on. for most of the week, the issue of gun safety dominated

the agenda in washington as vice president joe biden met with people on all sides of the fight over new gun restrictions. from the white house, nbc's kristen welker has more tonight. >> reporter: a month after the newtown shooting, gun stores tell nbc news they have seen an uptick in sales. owners stocking up out of fear the obama administration will impose stiffer laws. in december, the national instant criminal background check system reported 2.2 million background checks were performed last month, in increase of about 58% over the same period in 2011. >> you all know this is a complicated issue. >> reporter: and it is against this backdrop that the vice president is wrapping up his gun safety task force. >> federal weapons trafficking statute to universal background checks to making more widely available mental health assistance. >> reporter: there are more proposals, including the controversial reinstatement of the assault weapons ban, and

limiting access to high capacity clips. earlier in the wee biden butted heads with the national rifle association over those issues. >> the vice president and his folks are focusing primarily on firearms ownership, and what we consider second amendment rights for the american people. >> reporter: on friday, the vice president met with representatives from the video game industry and there was division about whether there is actually a correlation between games and real life violence. daniel greenberg, a gaming industry representative, says videos aren't the problems. >> what the science tells us is there is no causal link between imaginary violence in movies and books and video games, there is no causal link between imaginary violence and real life violence. >> reporter: reverend michael mcbride who met with biden with other religious leaders on wednesday says the white house encouraged them to reach out to their congregations. >> this is an opportunity for the faith community and for all americans to unite around the common pain of gun violence.

>> reporter: white house officials say the vice president has offered to meet with families who are impacted by the tragedy in newtown. he has said he's aiming to get his proposals to the president by next tuesday. lester? >> kristen, thank you. it's been three years to the day since the massive earthquake devastated parts of haiti. today, former president bill clinton attended a memorial service at a grave in which thousands were laid to rest. while some progress has been made, the suffering continues there on a vast scale. nbc's mark potter is there. >> reporter: three years after the earthquake, the haitian capital is bustling. the downtown rubble is cleaned up. buildings are under repair. the damaged presidential palace has been knocked down, and the famed iron market is again selling goods. still, with 70% unemployment, there are massive problems, and concerns that the promise haiti would be rebuilt better than ever is unfulfilled.

jonathan katz writes about haiti's reconstruction. >> there has not been a concerted effort to help build a strong, independent, competent haitian government and civil society that is able to handle its own problems. >> reporter: while more than a million people have moved out of evacuation camps, nearly 300,000 remain. amnesty international calls the housing shortage catastrophic. another continuing crisis is health care. >> cholera has been disastrous. over 6% of the population has been affected by it. over 7,500 have been killed by it. >> reporter: last year doctors without borders treated 20,000 cholera patients here. drawing lots of attention now is a recent announcement from canada, haiti's second largest aid supplier, that it is freezing further assistance citing corruption, a weak government and lack of progress. the haitian president agrees progress is slow, but blames private aid groups which got almost all the recovery money.

>> we're not lobbying for haiti to get all the money. but we are lobbying for haiti to have enough money where our institutions are not weakened. >> reporter: analysts say so far only about half the official relief money promised for haiti was actually spent here. mark potter, nbc news, port-au-prince, haiti. when "nightly news" continues on this saturday, why millions of computers may be vulnerable to a hacking attack and what you can do to prevent it. and later, where saying i do can make a big difference to a very important cause.

the department of homeland security issued a warning to users of a software program that many of us rely on because it could leave many computers wide open to hackers. nbc's charles hadlock has more tonight. >> reporter: just browsing the web is enough to allow hackers to gain access to the latest security hole in a product now on millions of pcs and macs. >> once you gain control of someone's computer remotely, you can do a lot of mischief. >> reporter: the problem is in java software. a computer language that runs in the background on millions of devices. some say it has become a favorite exploit for hackers, the target of two attacks last year alone. experts say java 7, the latest version for web browsers, contains a flaw that could allow cybercriminals to take over a computer.

>> you could attack their online banking, you can get into all sorts of funds transfers. >> reporter: anyone using browsers for pcs or macs is at risk. though apple has taken steps to block java and prompt users to install new updates. oracle, the maker of java, says in a statement it is aware of the flaw, but it is limited to the java for browsers product, adding a fix will be available shortly. but the u.s. department of homeland security is not waiting. on its website, it recommends people disable java. the latest security problem is the talk of the tech world. tech journalist leo laporte explained what to do on his weekly radio show. >> if you go to the settings of your browser, in safari on the macintosh on the security settings, uncheck the box that says enable java. >> reporter: experts caution users not to disable java script, a separate program not affected by the current flaw. charles hadlock, nbc news, dallas. this year marks the 50th anniversary of the assassination of john f. kennedy.

last night in dallas, jfk's nephew robert f. kennedy jr. spoke out about the assassination. kennedy said like his father, he questioned the warren commission report which concluded that lee harvey oswald was the lone gunman. he said he believed the evidence is very, very convincing that oswald did not act alone. up next here tonight, when getting married can make a difference to others in need.

saturday, of course, is a popular wedding day. and tonight how a wedding can make a big difference not just to those getting married, but to folks who need help. nbc's diana alvear explains in tonight's "making a difference" report. >> reporter: after the

champagne, the cake and the vows -- >> you may now kiss your bride. >> reporter: -- comes a check made out to a good cause. that's what you get when mary melfy officiates a wedding. instead of getting paid, the county clerk asks the happy couple to donate what they can to safe and hunterdon, a group that helps victims of domestic violence in new jersey. >> i love it. >> reporter: so many weddings, 150 of them a year. the conservative indian wedding where she had to omit the line you may kiss the bride, the couple who forgot their rings and had to make do with candy ring pops, and a favorite, the marine on home leave for just one week, to marry his sweetheart. >> i was crying. the staff was crying. >> reporter: after seven years, the money has piled up. >> with $100 and then $200, 2012, i hit the $20,000 mark. and it was just like hitting the lottery. >> reporter: donna vartos relies on mary's wedding donations. >> we provide days of shelter

and security to women and children who are fleeing from domestic violence, 365 days a year. in essence, mary's contributions enable us to keep the lights on. >> reporter: mary is determined by the time she ends her term as county clerk in four years she'll hit $40,000, sharing new beginnings for some, creating better futures for others, all thanks to love. diana alvear, nbc news. in a moment, we jazz it up at a place that is bringing a community together.

finally tonight, bringing jazz back to the neighborhood. here in manhattan, there are any number of famous jazz clubs that will pack them in on a friday night. yet it is a living room in an old brownstone in bedford-stuyvesant, brooklyn, that is quietly generating buzz among jazz fans and curious visitors for its downhome feel. ♪ jazz has come home to bedford-stuyvesant. the 19th century town home of deborah mcclain, where every friday night her parlor is transformed into a bygone era of late night jazz jam sessions. >> i remember when i first took over the house, i got the family together, and we played music. we danced. and we sang.

and all i could feel is that my grandparents had to have been very happy. >> reporter: the elegantly restored brownstone has been part of deborah's family for six generations. after converting it to a bed and breakfast several years ago, deborah began to look for ways to entertain her guests and build community. bassist eric lemon was looking for a way to revive the days when the neighborhood was the it place for jazz. >> it had a strong developed community since the '40s. i think the hip-hop world changed the way people listen to music. and just all of a sudden started participating, you know. >> reporter: and so the idea of brownstone jazz was born. ♪ ♪ come with me >> reporter: on a good night, 50 people will fill deborah's parlor, old, young, neighbors, tourists.

they pay the $20 cover for a night of music. ♪ >> brownstone jazz is a big old house party. >> reporter: and to enjoy the friday night fish fry during intermission. >> i mean, this fish is awesome. >> this is a sense of intimacy here and a sense of warmth. >> even for people that don't really know that much about jazz i think it is really easy to enjoy and be immersed in it. >> reporter: but there is more to this audience than first appears. as the evening unfolds, some of the patrons become performers in the open mike portion of the night. ♪ singers and instrumentalists, like myself, take turns in the

spotlight. ♪ [ applause ] >> it is the greatest music in the world. >> reporter: you ever get blown away if somebody from the crowd gets up there and plays and you had no idea? >> all the time. living right down the street, see them in the laundromat, on the bus, going to their day job. next thing you know they're back there, wow, i didn't know they could sing. ♪ >> reporter: it seems jazz never really left bed-stuy. it was apparently just looking for a place to call home. the brownstone jazz series is held at the sankofa aban bed and breakfast in brooklyn. it is one of the many cultural and musical series they host there.

on that note, that's "nightly news" for this saturday. i'm lester holt. i'll see you tomorrow morning on "today." have a great evening, everyone. good night. right now at 6:00, a rush to buy guns and ammunition here in the bay area. we'll show you how the national debate over gun control is impacting a gun show at the cow palace. also -- >> i can't reverse the pain that i've caused. but i can try and do what i can in the community to help. >> from convicted criminals to law enforcement officers, a diverse group of people set out to make a change in their city. and it's about to get even colder. we'll show you the freeze warning that's in effect for

parts of the bay area. nbc bay area news starts now. >> good evening, i'm diane dwyer. the debate about gun control took center stage today at the cow palace. organizers say it's their most successful ever in the bay area. our monty francis is in daly city with more. hello, monty. >> reporter: diane, good evening. some people told us they lined up as early as 4:00 this morning to get into this gun show. and organizers say there were triple the number of people here compared to last year. now, we have not been able to verify that last part, but it's fair to say that turnout here at the crossroads of the west gun show was large, and the lines during the day were quite long. you cannot just walk into the cow palace and walk out with a gun. that is because there's a ten-day waiting period here in california, but there are no such restrictions on ammunition. many people left with arge boxes