good evening. it has been almost a month of tantalizing clues and crushing disappointment in the search for malaysia airlines flight 370 and so the latest discovery is being met with caution and held breaths. an underwater signal, perhaps from one of the plane's black boxes, has been picked up by a chinese search vessel in the south indian ocean. for the families of the 239 people aboard the plane who have suffered so many false leads, the thought that once again the answer to this mystery could soon be in reach is at this point almost too much to hope for. nbc's ian williams is in perth, australia, where the search is being coordinated. ian, what 's the latest? >> reporter: good evening, lester. well, four weeks on and with time is fast running out for find the blag boxes, the latest reports have skbren rated some hope but also a good dose of cauti caution. the signal has the same frequency as that have that emit bid the plane's black box data reporter the report said they had yet to accomplish whether it is from the missing jet. it's also reported that a chinese aircraft spotted numerous white floating objects about 50 miles from the detection area. the search for the black box, which could solve the mystery of what happened to mh-370, has become increasingly urgent as its batteries last only about a month. but after weeks of searching, the chinese reports were treated with caution. the australia defense minister warn there had have been many false leads and a good number of them have come from china. >> they only heard this pulse for a minute and a half and the fact that they haven't been able to go back to that same spot and get another pulse, that's a big concern. >> reporter: the australian-led agency supposedly in charge of coordinating the search seems taken by surprise. in a statement tonight, it said that while the characteristics reported are consistent with the black box there is no confirmation at this stage that the signals or objects are related to the missing aircraft. the agency has asked china for further information. it's dawn here in perth and the search is now getting under way again with renewed intensity. the australian officials say they're looking to send fresh assets to that area where the chinese detected the sounds, lester. >> ian williams tonight. thank you. it was a foreigning point in afghanistan today as millions of men and women turned out to vote in a presidential election. president obama called it another important milestone as the u.s. draws down its forces there. our chief foreign correspondent richard engel is in kabul tonight. richard? >> reporter: good evening, lester. that this election even happened is an accomplishment. for weeks the taliban has been trying to stop it with a campaign of violence, attacking journalists and election workers and threatening to kill voters. but that campaign failed. despite all the threats, afghans came out to vote -- men and women lined up. >> we feel today it's really important. >> reporter: security was tight, the roads closed. president hamid karzai cast his ballot, but he's not running, banned under term limits. the next president is likely to be one of three former government ministers. all say they want u.s. troops to stay here beyond 2014. the afghan government says voter turnout was roughly 45% with around seven million votes cast. that's high considering anywhere else today would have been considered a bloodbath. a thousand polling stations, one in seven, had to close because of violence. 146 attacks on voters. still, afghans defiantly showed off their purple fingers, the indelible ink proof they made their mark for democracy these people are risking their lives to vote. they're doing their part. the question now is whether their votes will be counted fairly or is this all just for show? presidential candidate abdullah abdullah remains caution. he lost the last election in 2009 to president karzai in a vote that was widely considered fraudulent. >> the people this time around are very serious that their votes should be counted rightly and fairly. >> reporter: there are still 33,000 american troops here but today they were nowhere to be seen. earlier this week, we toured eastern afghanistan with major general steven townsend who said his forces were on standby. what are american troops doing to help with this election? >> that's a good question. actually, very much behind the scenes. the afghans truly are in the lead for this election. >> reporter: this was the first election afghans secured themselves. it was violent. the government nonetheless called it a huge success. but there is still a lot of time to manipulate results in the two weeks it will take the count the votes. it's unlikely that any of the candidates will win an outright majority. there will probably be a runoff so there might not be a new afghan government in place until this summer. lester? i. >> richard engel in kabul. thanks. a harrowing military rescue mission is under way tonight to save a california family and their sick baby stranded at sea. the family has set out to sail around the world when their boat lost power and they lost the ability to steer it. it's on unfolding nearly a thousand miles off the coast of mexico. nbc's miguel almaguer has the latest. >> we're totally stoked. there you go. >> reporter: eric and charlotte kaufman were living their dream, sailing around the world with their children, three-year-old cora and one-year-old lira. >> thanks for watching our cool video. >> reporter: along the way the young couple posted videos, pictures and blogs until they suddenly ran into trouble. after setting sail from san diego to the south pacific two weeks ago, the 36-foot "rebel heart" lost power and steering in rough waters 900 nautical miles off the coast of mexico a mayday call. little lira was seriously ill. >> this is what we train for. the rescuing is specialized in this capability with the combat shadow. >> reporter: the california air national guard and the navy launched rescue teams. but reaching the stranded family in the middle of the open ocean was risky. helicopters forced to refuel midair. then, after spotting the "rebel heart" rescue teams plunged into the water then boarded the boat. lira was safe but not out of trouble. >> she's stable but she's still critically ill. >> reporter: the kaufmans' extended family has been receiving updates but say it's still unclear what happened to lira. >> i'm glad that they're alive and that she's -- that my little niece is being taken care of. >> reporter: tonight, the navy plans to bring the kaufmans aboard this ship, nearly the end of their harrowing rescue. the family said to be in good spirits, though their high drama in the open ocean isn't over yet. miguel almaguer, nbc news, los angeles. three days after the shooting at fort hood that left three dead and 16 people wounded come the tough questions -- why it happened again and how it could have been prevented. nbc's mark pot we are that story for us tonight. >> on and off base, widespread concern for the families of those killed or wounded in the fort hood shootout. >> it's important to remember. if you fail to remember you're doomed to repeat. >> reporter: also front and center is the issue of soldier mental health. with portable v.a. counselling units in place and congressmen visiting. >> i think we have to do a better job of reaching out to our young men and women coming back from harm's way. >> reporter: the army says the gunman, identified as specialist ivan lopez was under psychiatric treatment when he brought the unregistered murder weapon on base. he's accused of killing stf sergeant carlos rodriguez, sergeant timothy owens and sergeant first class daniel ferguson. >> obviously we have a gap. any time we lose an individual something's gone wrong. >> reporter: it's been an issue for several years. in 2010, a year after the first fort hood shooting rampage in which 13 were killed, the department issued an independent report on protecting the force, lessons from fort hood. among its findings -- "we must be alert to the mental, emotional and spiritual balance of service members, colleagues and civilian co-workers and respond when they appear at risk." many believe the army hasn't moved fast enough on this issue and now see the latest fort hood shooting as another wakeup call. >> i think this whole incident is going to motivate the military establishment to find some way to identify much more quickly people who have problems and more importantly do a much better job, a swifter job of getting these people out of the service. >> reporter: the fort hood commander says no permanent changers and operating procedures have been made yet but they're under review after two shooting sprees now at the same place. and as officials debate the need for policy change, a fort hood memorial service is scheduled for this coming wednesday to honor the latest round of fallen and wounded here. lester? >> mark, thank you. the first funerals were being held today for the victims of the mud slide in washington state two weeks ago. there are new questions tonight about whether more could have been done to keep people out of harm's way. we get more on this from nbc's joe fryer. >> reporter: the deadly mud slide in oso, washington, took so much. >> never in my wildest dreams i thought something like that would happen. >> reporter: seth jeffords lost his wife christina and four-month-old granddaughter. you've lived in that neighborhood for 16 years. were you aware of any risk at all? >> not of that. >> reporter: the mud slide has raised many questions, especially for seattle attorney karen willie who specializes in cases about landslides. >> any time i first hear about a landslide my first question is has there been a landslide there before? >> reporter: in this case, the answer is yes. the same hill saw slides in 1949, '51, '67, '88 and 2006. >> and to have five of them? that's a lot of landslides. >> reporter: the river cuts into the toe of the sloped hill causing erosion and increasing the risk for slides. a 1999 draft report commissioned by the u.s. army corps of engineers to study the impact on fish warned of the potential for a large catastrophic failure in this area. another draft report in 2000 said the hill posed a significant risk to human lives and property property. >> was this known? did people understand this? >> reporter: then in 2004, snohomish county's own documents show officials considered buying out homes in the neighborhood saying the cost would be significant but would remove the risk to human life and structures. instead, county officials recommended stabilizing the slope, saying the landslide risk could be reduced or eliminated. before that could be finished, in 2006 a slide struck. no houses were hit, but massive amounts of mud clogged the river, threatening to flood several holmes. seth jeffords, who lost his family this most recent slide, was among those who evacuated as a precaution in '06. >> we're packing up our stuff and getting out. >> reporter: after that, records show snohomish county placed barriers in the river to help stabilize the area and many neighbors thought they were safe. >> they implied the that the problems were fixed. >> reporter: you felt the problem was solved? >> yeah. >> reporter: with the first of many funerals beginning and the search for victims ongoing, snohomish county officials are declining to comment on their past efforts to address a slope with a turbulent past. joe fryer, nbc news, oso, washington. >> when "nightly news" continues on this saturday, taking leave from work after a baby is born. how american men are getting the short end. and later, why a time capsule reveals about life in america a family secret left almost half a century ago. we're back now with a heated national debate tonight about paternity leave and whether new fathers get enough of it. it all started when a radio host criticized a professional athlete this week for taking a couple of days off. nbc's craig melman, a new father himself, has the story. >> playing second base, number 28, daniel murphy! >> reporter: second baseman daniel murphy may be used to be criticized for his play on the field. but this week sports radio skewered him for missing the first two games of the season for his son's birth. >> he gets [ bleep ] to your team and you play baseball. that's my take on it. what -- there's nothing you can do anyway. you're not breast-feeding the kid. >> it was a c-section before the season starts i need to be at opening day. >> the backlash was immediate and the controversy started a national conversation. >> we should have opportunity to spend time with our kids. >> there's certain seminal moments in your life you don't get back. >> esiason has since apologized but while there may be a cultural shift in the way americans view paternity leave, the law has not caught up yet. currently, 62 countries have laws requiring paid paternity, russia, rwanda and cambodia among them. not on that list? the u.s. the family medical leave act guarantees fathers up to 12 weeks of unpaid leave but only about 14% of companies offer paid leave. mine is one of them. so when my son was born last month i took two weeks of paid paternity leave and i wouldn't trade it for anything. it wasn't nearly enough time to bond with him. but even when it is available, experts say many men are reluctant to take any time off. why aren't more men taking it? >> i think they're still concerned that they're going to end up damaging their professional reputation. whether they'll the b passed over for a promotion or they won't get an opportunity to advance their careers. >> reporter: companies like bank of america, facebook, and yahoo offer generous paternity leave. but it will likely be a while before paid leave for new dads becomes the norm. nbc news, new york. >>. we're back in a moment with a new look inside america's long civil rights struggle. . you're looking at the sun unleashing a stunning and powerful flare. the remarkable images captured by nasa this week. they were just released today. solar flares are powerful bursts of radiation that do not affect humans on the ground but, depending on the intensity, they can interrupt things we rely on like gps and communications signals. this was the scene in ecuador, the volcano known as the throat of fire shooting a six-mile column of lava and ash into the air yesterday. the 16,000 foot volcano last erupted in february but has been classified as active since 1999. 46 years after the assassination of martin luther king, jr., the national civil rights museum reopened today in memphis hoping to bring a new generation into this country's civil rights narrative. nbc's ron allen has the story. [ cheers and applause ] >> reporter: with that, a new era begins for the national civil rights museum. it was until that unforgettable moment in american history just a typical memphis motel. >> martin luther king, jr. was killed tonight in memphis, tennessee. >> reporter: king was assassinated on the balcony of the lorraine motel 46 years ago this weekend and, like the powerful images of that moment, the motel was preserved in time. king's room, number 306, as it was for visitors to see, lunch, the day's newspaper still there. >> this museum after 22 years needed to be updated, needed to be engaging to a younger generation. >> reporter: 18 months and some $30 million privately contributed dollars later it's more dynamic and interactive and expanded beyond tributes to icons like rosa parks. new exhibits explore five centuries of history, starting with the slave ships that crossed the atlantic. high school principal kimberly martin says her students will learn a powerful lesson. >> overcoming adversity. they're going to know that whatever sets you back, whatever gets you down you can overcome it. >> come here and you'll understand in a very different way what this great country is really all about. >> reporter: russell watson and lesley more understand. they were seine station workers on strike back then who king came to memphis to support. >> we thank god that other people are still here to keep that dream going on. >> reporter: king's dream and the dreams of so many others are what this place that many consider sacred is all about. ron allen, nbc news. coming up, a man gets an unexpected gift from his late wife. what was found in a time cab pse that brought him to tears. finally tonight, inside the walls of a phoenix home, a look at the past almost a half century later. a time capsule details a different world and it's the remarkable discovery of who left it behind that's unearthing even more memories tonight. joe dana from our phoenix affiliate kpnx has the story. >> reporter: sometimes in life we draw up blueprints but fate has other plans. >> wow. i just think i'm going to value people a little bit differently. >> reporter: that lesson hit home recently for contractor john murray. see, while knocking down walls of this 1950s north phoenix four bedroom, john discovered the contents of a partially opened time capsule. >> we've done hundreds of houses, i've never seen anything like this. >> reporter: there was a photo of a family from another era and an open letter written from a future generation. >> this capsule is being buried on september 27, 1966. >> reporter: the message penned by a 33-year-old betty klug. >> the vietnam war is still going on. racial situation very serious. boys have long hair resulting from the beatle craze. >> reporter: it turns out betty's husband bruce, now 79 years old, lives in scottsdale. as john presented the contents of the time cab sewell to brupst was all new to him. >> this is what we found. there's a picture there. >> reporter: bruce was unaware his wife left this behind. betty followed politics closely. >> barry goldwater republican candidate for president. >> reporter: and then bruce realizes the date the letter was written. >> on september 27 -- that's my birthday. >> reporter: the letter would become a delayed birthday gift to bruce. ten years after she deposited the time capsule in the walls of their home, betty died in a car crash. >> i don't know how i did it. went back to work within a week. >> reporter: for a few moments on this afternoon the letter would unearth old memories. >> that's where we met, oak park. >> reporter: each sentence prompting a precious recollection. >> and she was so dam smart. >> reporter: time capsules provide observations about politics and culture but bruce says if there's a message here it's the value who you love because, as bruce will tell you, things don't always go as planned. >> we had the best marriage. not once did we argue about anything. >> reporter: for nbc news, joe dana, scottsdale, arizona. that's "nbc nightly news" for this saturday. i'm lester holt reporting from new york. see you tomorrow morning on "today" and right back here tomorrow evening. good night. right now at 6:00, store clerks fight back with surveillance cameras rolling in the east bay. what the police say about the vigilante vendors. another cal student comes down with a highly infectious disease. they're asking students to take action to protect themselves. the chinese government says it has a new clue about the whereabouts of the malaysian airline jet. is this the break they've been hoping for. good evening. i'm terry mcsweeney. >> and i'm diane dwyer. we begin in the east bay. two store clerks took matters into their own hands, instead of giving up the cash, they fought the armed robber, and it was all caught on tape. kimberly tere joins us from police headquarters in san leandro with more on what happens. kimberly? >>. >> reporter: diane, those two cashiers weren't actually able to detain the suspect, but they scared him enough that he took off and left behind his gun, which police say could be valuable evidence in this case. look at the surveillance video taken inside of the store. on the 300 block of east 14th street around midnight. according to police, a man wearing a ski mask, armed with a handgun, walked into the store and tried to rob the two employees working at the time. that's when police say the two