other side. we'll continue to follow this story and other local stories coming up at 6:00. on our broadcast tonight, poison scare. letters laced with ricin now sent to the president, the mayor of new york city, and others as the fight over gun control has apparently now taken a threatening new turn. on alert. in a state already so hard hit, a wave of tornadoes in oklahoma again tonight, not far fro where the remnants of a landmark school from the last school were torn down just today. and the graduates. one of our favorite nights of the year around here when we get to show you the very best of this year's commencements. "nightly news" begins now. good evening. the first scare of its kind took place in those nervous and shaky

days after 9/11. prior to that, few people had ever heard of ricin, very few of us ever dreamed someone would send any kind of substance through the mail designed to harm and threaten people. now it has happened again. letters to the president of the united states and the mayor of new york city have been intercepted and they test positive for ricin. this time they appear to be linked and they are about the divisive issue of gun coal post newtown. this is now an fbi matter. it's where we begin tonight with our justice correspondent, pete williams, in our washington newsroom. pete, good evening. >> reporter: brian, the president and the mayor were never in any danger because their mail is routinely screened for hazards like this, but a third letter did get through. its recipient is said not to have been harmed. so, the question tonight is who sent them? law enforcement officials say the letter addressed to president obama was found today at a mail screening facility in

washington nowhere near the white house. it was similar, they say, to letters mailed last week containing a short note making threats against advocates of gun control. one addressed to new york mayor michael bloomberg was found last friday at the new york city facility that screens mail bound for city hall. the mayor was taking it in stride. >> there are people who i would argue do things that may be irrational, do things that are wrong, but it's a very complex world out there and we just have to deal with that. >> reporter: a nearly identical letter was sent to an office building in washington, d.c. and opened monday by mark blaze, director of bloomberg's organization mayors against illegal guns. officials say he was not harmed by the contents. all three, investigators say, were post marked in shreveport, louisiana, and mailed ten days ago on may 20th, and all contained a material that initial tests say was a form of the deadly poison called ricin, made from the beans or seeds of

the castor plant. those same beans are the source of castor oil, widely used in making medicines, but if correctly processed, they can also yield a deadly poison for which there is no known anecdote. >> it basically will deploy the tissues that it touches. so, if you inhale it, it would give you lung damage. if you ingest it, it would give you damage to your gut. >> reporter: a month ago, federal prosecutors charged a mississippi man, james everett dutschke, with mailing letters of ricin to president obama and a senator of mississippi. both were stopped at mail screening centers. and the fbi arrested a man in spokane, washington, last week, accusing him of sending threatening letters containing ricin to a federal judge there. as for the potential penalties for sending letters containing ricin, the mississippi man faces a biological weapons charge. it carries a maximum sentence of life in prison. he has denied doing anything wrong, brian. >> pete williams starting us off from d.c. tonight. pete, thanks. we have an update on a

deadly shooting connected to the expanding investigation into the boston marathon bombings. you may have heard last week a friend of the bombers' was shot and killed while being interrogated by the fbi. today, that man's father back home in russia, said his son was killed execution-style, shot seven times by the feds, including once in the back of the head. the fbi initially said their agent shot the man when he lunged at them with a knife, but now the fbi says he was holding a metal rod. they feared he was going to reach for a gun. president obama is set to nominate a new fbi director. former deputy attorney general james comey, a republican who famously broke with president bush back in '04, refusing to reauthorize the administration's controversial warrantless wiretapping plan. as u.s. attorney for the southern district of new york, he oversaw the prosecutions, among others, of martha stewart, executives of worldcom and

international drug dealers. comey would succeed robert mueller whose term ends in september. the fbi director is a ten-year appointment. turning now to weather. yet another dangerous night of it, especially where folks can't afford any more bad weather. while it stretches from the north in wisconsin all the way down south to texas, oklahoma got hit again today. late this afternoon, we looked up and saw this striking image. that's weather channel meteorologist mike bettes standing beneath an enormous cloud bank as part of the approaching front. well, mike is with us live now, having reached a point outside of tulsa, oklahoma. mike, good evening. >> reporter: brian, good evening to you. another active day of storms right here in tornado alley, and multiple tornado touchdowns. we know large tornadoes have touched down in arkansas and brief tornado touchdowns right here in oklahoma. to say the least, these storms have been menacing. some of these storms that we chased formed these wall clouds

that reached almost all the way to the ground. the sky has gone midnight black in some instances. large hail, wind and brief funnel clouds with many of these storms, and the threat is still ongoing this evening and likely will go on for at least the next 24 hours. we think we have a risk that extends now from the central plains, including oklahoma city yet again. it's been an ongoing event for two weeks now. this event tomorrow could extend all the way into the upper midwest. that could include the twin cities, minneapolis and maybe all the way to cleveland, ohio. tornadoes likely in many states tomorrow as we wrap up the workweek, and then it doesn't stop there. the threat will also continue with rain, heavy rain from oklahoma city and then south and east through dixie alley, as it's known, the southern states and right into tennessee and maybe eventually into atlanta, georgia, as well with flash flooding in many places. if there is any silver lining to this, brian, farmers we talked to say we'll take the storms any time, we need the rain. they've gone through a multiyear drought here in the plains. >> mike bettes outside tulsa,

thanks. and here we are talking about oklahoma again. the live chopper shot is from our affiliate kfor in oklahoma city. again, unbelievably, moore, oklahoma, is among the places under the threat of tornadoes today into tonight after what was another emotional day there. nbc's janet shamlian is there for us tonight alongside the remnants of plaza towers elementary school. >> reporter: even as dark clouds gathered above them, demolition crews went to work on what was left of plaza towers elementary school. what the tornado started here, bulldozers worked to finish. >> sad. hard to see it go. this is our little neighborhood school. >> reporter: with former students watching and seven crafted crosses standing in contrast to the plywood wreckage, this is more than just another building ravaged by the storm. seven children lost their lives here. it's become moore's touchstone, the unofficial memorial. >> she was the there that day. i got her out before the storm hit.

we just wanted to come see it one more time. >> reporter: the work came amid a barrage of tornado watches and warnings throughout the oklahoma city area, including moore. >> central oklahoma, just like last week, is certainly impacted. chasing today, impressive view of the storms. large towering supercell thunderstorms as they are known with a lot of hook echoes today. and hook echoes on supercell thunderstorms is very bad. that's what meteorologists look for and that's what contains the tornado. >> reporter: residents already on edge being told again to take shelter. >> rapid motion. tornadoes in this thing. could touch down any second. >> it's on the ground. there are stud fingers on the ground. >> and now the tornado sirens are going off here in cushing, guys. >> reporter: numerous reports of tornadoes and some damage, but so far no indication that anyone was seriously hurt. ♪ >> reporter: today's storms in the wake of wednesday's benefit concert for victims of last week's tornado. music stars from across the country, many of them from oklahoma, performing for the healing in the heartland event in oklahoma city. money raised will come here for

the rebuilding. they just can't seem to catch a break here. they're trying very hard to move forward with projects like this, but amid the sirens, the warns to take cover and reports of even more tornadoes, brian, that is proving very difficult to do. >> it's unbelievable, janet. they sure could use a break. janet shamlian back in moore, oklahoma, tonight. thanks. let's turn overseas now. a troubling new turn in the crisis in syria as the debate over arming the rebels continues president assad says his forces have their hands on new weapons from russia. all this as we get our first close-up look tonight at how the war in syria is now spilling over into neighboring lebanon. our chief foreign correspondent richard engel has made his way into the city of tripoli, lebanon, and has our report tonight. >> reporter: president assad claims he has taken delivery of russian missiles with more on the way. russia has promised assad advanced anti-aircraft missiles, but the rebels don't have

planes. instead, such missiles could shoot down western planes, enforcing a possible no-fly zone or fend off israeli air strikes like this one last month in damascus. assad's interviewer, a lebanese station owned by hezbollah, which backs assad and sends fighters into syria. but now the fighting extends beyond syria. over the past two weeks, dozens have been killed in tripoli, lebanon's second largest city. shiite muslims, assad supporters, and hezbollah fighting sunnis who back the syrian rebels. at night, gunfire. at sunrise, fighters in the streets. this coffee shop owner told us "everyone here has guns at the ready." he keeps pistols hidden under his coffee machine. he doesn't hide the black flag

outside his shop, a sign to sunnis he's one of them. the lebanese are drawing battle lines. at a radio station, a prominent sunni cleric told us he fears the violence in tripoli will soon spread. we headed to the citadel where the fighting has been most intense. this is the front line in this lebanese city. the syrian civil war has already come here. lebanese troops have now moved in to try and keep the two sides apart. the lebanese army want to be peacekeepers, but even with armored vehicles, they are not as strong as hezbollah, and sunni gunmen ignore them. this country suffered its own civil war for 15 years. it may now be sliding into syria's civil war as well. richard engel, nbc news, tripoli, lebanon. still ahead for us tonight, a growing trend among retirees opening their homes, expanding their families again because the nest is empty. and later, an annual tradition as we salute this

year's graduating class in spectacular fashion.

>> announcer: the road to retirement, brought to you by fidelity investments. take control of your personal economy. it's quite a stat to try to get your mind around. every day in this country, 10,000 americans, members of the baby boom generation, turn 65, the traditional retirement age, and in something of a new development, some members of this generation have decided it would be a good time to add to their families. our report tonight from nbc's chris jansing. >> you're so cute. >> reporter: the woodfork family story is chronicled in photos. a 43-year marriage, three children, now grown. and the latest chapter written when ann and nelson were both 65 and approaching retirement. they adopted a 17-year-old. and did people think you were nuts? >> totally. >> reporter: it wasn't an empty nest that motivated them but the

idea that someone like shakorn adams would soon age out of a lifetime of foster care. >> if i didn't become adopted, i would have been on the street as an 18-year-old, i would be considered an adult and i would have nowhere to go. >> reporter: the woodforks' bold decision gave shakora a home. >> i wake up and say, wow, this is where i live. >> reporter: you get up and a mom and a dad and a home and all that stuff, right? >> yeah. yes. it's amazing. >> reporter: while no one tracks exact numbers, experts say more older adults are adopting, often older kids. >> people are getting married later, they're having children later. the reality is there is a big gap between parents' age and childrens' age in a lot of families today. >> reporter: and the need is great. in the most recent government study, 104,000 foster children were waiting for adoption. boomers can help fill that gap. they are staying healthier, living longer and have the time and means. but do they have the energy?

>> it's not like chasing toddlers. >> yeah, in some ways it's kept me young. it's kept me on my toes. i have to think about things that i wasn't thinking about. >> looks really nice. >> reporter: this week shakorn has prom and a day he never expected to see -- high school graduation. >> so psyched. i'm so happy. like, i don't even know how to explain it. >> reporter: and one more thing shakore never dreamed -- graduation will be a family affair. >> our adult kids are all coming home for it. they're excited about it. >> the same kids that thought we were crazy. >> yeah. >> reporter: a new kind of family redefining the sunset years. chris jansing, nbc news, swanscot, massachusetts. and we're back in a moment with a possible new development in one of the enduring mysteries of the modern era.

his name is e. gordon gee. he is the popular and outspoken president of ohio state university. he is getting himself out of some hot water tonight for what

he said about negotiating with notre dame over joining the college football big ten. the "ap" quoted him as saying, "the fathers are holy on sunday and they are holy hell on the rest of the week. you just can't trust those damn catholics on a thursday or a friday." gordon agree gee said today that he was deeply sorry for what he called his poor attempt at humor. one of the best known liberal figures in the catholic church has died. father andrew greeley was a lot of things, including parish priest, intellectual and prolific author. he wrote over 150 books, including his first mystery novel, "the cardinal sins," which sold millions of copies. he was a relentless critic of the church while committing his life to it until the end. andrew greeley was 85. a team of archaeologists says it's made a promising discovery involving the disappearance of amelia earhart. a grainy sonar image captured

near an uninhabited island in the pacific they say could be the wreckage of her aircraft, which vanished back in 1937. the group, which has long been investigating her disappearance, says the image shows an anomaly under the water about 350 miles from the island, her planned destination that day. we are back in a moment tonight with a "nightly news" tradition as we chronicle a great american tradition this time of year -- the messages for the graduates and the college class of 2013.

as we said earlier, our final item here this evening is perhaps our favorite yearly "nightly news" tradition. tonight we get to salute this year's college graduates, the class of 2013. and we now share with you some of the very best send-offs this year. we fanned out on campuses across this country to capture the pride and the joy. >> i hope that you never lose sight of what brought you to this day. >> i'm about to graduate! four years. >> i'm so excited. i can't believe it. this is too incredible. >> you will be prepared for

whatever comes next, whatever comes next. [ cheers and applause ] >> you face the world of uncertainty. don't fear that uncertainty. embrace it. use it. >> there's no script. live your life. be in this moment. be in this moment. now be in this moment. >> it may seem all that's left for you is unpaid internships, monday to tuesday mail delivery and, thanks to global warming, soon semester at sea will mean sailing the coast of ohio. ♪ and always look on the bright side of life ♪ [ whistling ] >> you only live one life. don't spend it in safe, shallow water. launch out into the deep. if you meet a person you love, get married! ♪ i belong with you

♪ you belong with me ♪ you're my sweetheart >> still, to us, you will always be our baby. from every changed diaper to every shoulder ride, every bedtime story, every fight over curfew. all of the triumphs and the failures rolled up into one. >> she's going to be amazing. >> oh! >> so many good times. >> i'm so proud of you. >> you did it! i'm so proud of you! >> we are so proud of you all. ♪ can't do it alone, i can't do it alone ♪ >> you are all incredibly lucky. if you live in aleppo, syria, today, your main concern is staying alive. you have choices.

don't squander this opportunity. >> when bombs went off in boston and when a malevolent spree of gunfire visited a movie theater, a first grade classroom in connecticut, we saw citizenship. in the aftermath of darkest tragedy we have seen the american spirit at its brightest. ♪ >> i think it's really made everybody open their eyes to how short life really can be. >> we have to do our best to make the world a better place so things like that will never happen again. >> three, two, one. i'll get all your e-mail addresses. [ laughter ] we call our online world a community, but that's just to make us feel better. it's not. this is. people to your right and left

with hopes and dreams and fears. >> keep learning as you go. acknowledge that there will be fear and adversity. then go out and kick butt. [ cheers and applause ] >> today, i am optimistic. >> today, i just feel so grown up. >> today, i am inspired. >> today, i am feeling like a ground-breaker. >> today, i feel absolutely fantastically happy. >> today, i feel blessed and excited. [ cheers ] >> mom, i made it! i did it. >> today, i am a graduate of the class of 2013. >> and that was the magnificent hard work of producer katie yu and editor irene trulinger and countless producers, photographers, camera crews on all those campuses. we parents of class of 2013

graduates all want to say congratulations. we're so very proud of you and we're very sorry we turned your bedroom into a den. that is our broadcast for this thursday night. thank you for being here with us. i'm brian williams. we'll look for you right back here tomorrow evening. good night. and good evening, i'm raj mathai. >> we begin in the bay area, many members are walking out. the members at the santa clara unified school board are accused of working in a difficult environment, leading to the exit. how bad is it? >> reporter: it sounds pretty bad, i spoke with board members, one of them, michelle ryan was

warned how political it could get at santa clara unified school district and says it has all been confirmed in the last few months. she says it is a small group of parents and staff that created the controversial atmosphere. and we've seen that kind of activity before, but what we don't usually see is this, a student taking on the district and not mincing words. he is almost done with his junior year, the 17-year-old is not just studying for finals but is getting ready for take on the board members of the school district. >> i called them, they were a little incompetent. >> reporter: there was much more to say in the letter read at the board meeting. he called the board members juvenile, arguing, behaving inappropriately at meetings. so why the tough words? he says the research into the district began when he learned his principal was leaving at the