steps. >> well, today is young. >> i do not have one. see you at 6:00. on the broadcast tonight, hitting back after having their data mining operations revealed. today the feds revealed just how many terrorist attacks have been prevented because of it. is it a disease? tonight, the ama is recommending a relabelling of obesity. and this will impact millions of americans who struggle with it. ist real this time? is it really him? as searchers seem to nrow in on a field in michigan because they've been told it's where jimmy hoffa was buried alive 38 years ago. and creature comforts. when you're feeling at your worst, like allowing a very close friend to stay with you at the hospital. "nightly news" begins now.

good evening, after damaging leaks from a young american who has since fled overseas, today it was the government's turn. the head of the nsa told congress and tried to reassure the american people they're not only not listening in on the conversations of average americans, but the communications they have monitored through data mining operations have in fact stopped, they say, dozens of preplanned terrorist attacks in the post 9/11 era. all of this as individual americans are still sorting out how they feel about how much information is out there and how many people are monitoring all of it for suspicious activity. it's where we begin again tonight with our chief foreign affairs correspondent andrea mitchell. >> unclassified information. >> reporter: the head of the nsa general keith alexander, defended the controversial surveillance programs and denounced edward snowden for exposing them. >> the intentional and irresponsible release of

classified information about these programs will have a long and irreversible impact on our nation's security and on that of our allies. >> reporter: he revealed details of only two previously unreported cases the fbi says were cracked with the help of these programs. a plot to blow up the new york stock exchange between 2007 and 2010. the fbi said a kansas city man, khalid ouazzani, a naturalized citizen, was channeling money to al qaeda operatives in yemen who were planning to blow up the exchange. ouazzani ended up pleading guilty to bank fraud and money landering. >> would you say their intention to blow up the new york stock exchange was a serious plot? or is this something that they kind of dreamed about, you know, talking among their buddies? >> i think the jury considered it serious since they were all convicted. >> reporter: a second case of a san diego man allegedly financing a terrorist group in somalia. the fbi said it got on to him through the nsa database. enter edward snowden.

a foot soldier in an army of contractors with top secret clearances. the nsa says his leaks jeopardized these intelligence tools. >> we have too many people who have access to top secret clearances. as a result of that you have people who are not fully vetted and this may be the case with mr. snowden. >> reporter: but a former cia official says you can't stop leakers. >> it suggests can you stop someone from thinking they should do something like edward snowden has done. and stop them at the border before you know they're going to do it. i don't understand how you can stop this. you can't police somebody's thoughts. >> reporter: still intelligence officials shellshocked by the leaks are rethinking the system. >> we have to look and say, how did he do that, what did he do, where was that. >> reporter: even the president on pbs defended them. >> my concern has always been not that we shouldn't do intelligence gathering to prevent terrorism, but rather, are we setting up a systems of checks and balances? >> reporter: tonight there are reports still that snowden is still believed to be in hong

kong, has asked an intermediary to help him seek asylum in iceland. even though officials believed he made off with 1 million separate documents. brian? >> andrea mitchell in our d.c. newsroom starting us off again tonight. andrea, thanks. president obama has flown on to berlin tonight after wrapping up the g8 summit in northern ireland. the president will spend two days in germany. among other things, he will speak at the brandenburg gate 50 years after john f. kennedy visited the landmark that divided east and west berlin during the cold war. earlier the president and all the other world leaders posed for the official photo, under ominous skies, a fitting backdrop for how the talks went at times. especially given the split with putin of russia over his continuing support of the assad government in syria. after fighting this nation's longest war in afghanistan for the past 12 years, now the u.s. is talking to the taliban. it's one of two big headlines from there tonight.

the other is the official transfer of the fighting duties to the afghan forces from our bureau in kabul. our report from nbc's duncan golestani. >> reporter: a suicide attack today in central kabul, a reminder of how volatile afghanistan remains after almost 12 years of war. on a day when afghan forces took charge of their own security across the country. >> for the people of afghanistan, this is equally and perhaps more a great day. >> reporter: afghanistan won't just be fighting the taliban, now they'll be talking to them, and so will the united states. the taliban opened up at a news conference in qatar indication. today, even held a news conference. still intent on liberating afghanistan as they put it, but promising not to, quote, harm other countries. >> it's good news. we're very pleased with what has

taken place. >> reporter: state department officials say this is just the first step. the taliban have yet to renounce al qaeda or embrace afghanistan's constitution, including the rights of women. in kabul's tea shops, uncertainty about talking to the enemy. do you think the taliban is ready to negotiate peace? >> if they are ready, they have to stop killing innocent people. you have to stop the bombing. >> reporter: as of today, it's up to afghan forces to do the fighting. scores are being killed each week. the lieutenant and his men patrolling one of kabul's most dangerous intersections say they are ready. they're confident they can take on the taliban. duncan golestani, nbc news, kabul. >> and the pentagon has announced a timetable for one of the biggest policy changes ever undertaken by the u.s. military. integrating women into front line combat positions over the next several years, including some of the very top flight units. our pentagon correspondent jim miklaszewski has more on that story tonight.

>> six. >> seven. >> reporter: it's the ultimate all boys club. [ gunfire ] >> reporter: the grueling, physically demanding training to become an elite u.s. navy s.e.a.l. has always been closed to women. but under pentagon orders, that could change. >> we're looking for smart, qualified operators. you know, there's just -- there's a new dynamic. the days of rambo are over. >> reporter: military services have been ordered to open nearly 240,000 combat related jobs to women in the next three years, which could even include frontline combat roles in special forces like the army rangers and navy s.e.a.l.s. that could be a tough challenge. physical standards will not be lowered for women. load the tank round has got to be one that's done by a male tank gunner or a female tank gunner. we don't have different size weight rounds for them. >> reporter: there's also serious concern about the effect on young men and women isolated

in small units under the stress of battle. >> i'm actually more concerned with the men, and their reaction to women in their formations. quite frankly. >> reporter: but women have already been battle tested under enemy fire in iraq and afghanistan. 150 u.s. service women have been killed in combat in the past 12 years. army first lieutenant audrey griffith has little doubt. we first met her last summer, when she passed the army's course for combat engineers, one of the military's toughest combat training schools. she believes if women are given the chance, they'll make the cut. >> i think if you just keep letting women get the same training as our male peers, there's not going to be a question of, is it a male or a female. >> reporter: officials stress that no final decisions have been made. and it could still be years before women join the combat ranks in any numbers. as for first lieutenant griffith, she's deployed today on the front lines of southern

afghanistan as a full fledged combat engineer. proof again that many women are already up to the challenge. brian? >> jim miklaszewski at the pentagon for us tonight. jim, thanks. we have seen in the past couple months, a lot of pictures from foreign countries where people have flooded into the streets in protest, often fed by social media, often suppressed by the government. and now, tonight, it's brazil. big protests have developed out of nowhere, driven by economic injustice mostly. the biggest of them just last night, and again this evening. our report from nbc's mark potter. >> reporter: an estimated quarter million brazilians took to the streets in more than a dozen cities. most were peaceful, though there was violence. demonstrators in rio de janeiro attacked the state legislature building, throwing firebombs and confronting police. at least 20 officers and 10 protesters were reportedly injured. many in the crowds complained

about rampant corruption, crime, low wages, and a lack of social services. we lack investments, he says. mainly in health and education. as brazil spends billions to build stadiums for next year's world cup and the 2016 olympics. >> when you have a population of 13 million people who are going to bed hungry every night, it's hard to justify building so many stadiums with public funds. >> reporter: tensions have been building for weeks, sparked by a government increase in bus fares, and quickly escalated with images of police cracking down on demonstrators. it comes on the heels of other protests half a world away, egypt, greece and turkey. organized with the help of social media, building on popular discontent. brazil's president a target of some protesters, posted a statement on youtube, saying they had valid complaints and needed to be heard. but with brazil about to move on to the world stage with international sporting events,

not to mention hosting the pope next month, many wonder if it will be ready. tonight, even more protests are underway. mark potter, nbc news. a rare and scary sight out west this afternoon. that would be a funnel cloud to the east of denver international airport. not the kind of thing you see every day. luckily it moved on away from population centers. passengers were sheltered. terminals were completely emptied. flights as you might imagine were diverted as a precaution. in the end, we're happy to report no injuries or damage reported. now to the medical news that broke late in the day. tonight for the first dime, the american medical association says obesity should be recognized as a disease. our chief medical editor dr. nancy snyderman with more on what this means. this will generate a lot of talk. >> and boy, it has been percolating for a while, brian. it's controversial, and even doctors within the ama and the general community are divided. some think it's genetics and brain wiring, others say it's

the environment and self-restraint and the ability to push oneself away from the table. but nonetheless, the ama has now staked its claim. although it's not legal, the ama has a lot of clout in washington. their big thing is this can help with prevention and treatment. while the insurance companies are likely to push right back, it does mean there's going to be a change in conversation, and you're going to hear people say, brian, i'm not fat, i'm not obese, i have obesity. consider heart disease, diabetes, cancer, it's a whole new category, a whole new data reference list. >> it's going to be a big story. dr. nancy snyderman here with us tonight. thank you, as always. now to the big search going on in a vacant field outside detroit, michigan. the latest dig site in the ongoing search for jimmy hoffa. this time, however, there's a new seriousness about it because it's based on a tip from the son of a former mob boss who says hoffa was buried there alive

back in july of 1975. nbc's katy tur is in oakland township, michigan, for us tonight. katy, the search for jimmy hoffa, where hoffa's buried has become a part of the american lexicon for two generations. >> reporter: it certainly has. now they just stopped digging for the day here a few moments ago. they've been searching for the last two days. right now it looks like an archeological site than a crime scene. of course, they were led here, as you said, by a man named tony zerilli, the son of a detroit mob boss who said he was told hoffa was taken to a barn here after he disappeared in 1975. he was then hit in the head with a shovel, buried alive in a shallow grave and covered in cement. now, this is one of the greatest mysteries of the 20th century. what in the world happened to jimmy hoffa? the fbi has been searching for 38 years, spanning across michigan, to the end zone of the

meadowlands. so far, though, nothing. zerilli says he's 100% positive hoffa is in this field behind me. law enforcement sources tell me, he is so credible that if they don't find hoffa here, they may never find him. brian? >> katy tur outside detroit for us tonight. katy, thanks. still ahead, the big problem in the great lakes. the water levels hitting historic low levels and drying up a big part of the american economy. and later, the healing power of a familiar face from home. pets now allowed, even encouraged at a growing number of hospitals.

the great lakes contain one fifth of the fresh water supply in the surface of the earth. that may seem like a great deal of it, these days it's not enough for the level of commerce that those five truly great lakes have supported for so long. the problem is the water levels. the lakes are currently low and getting lower. our report on the impact tonight from our chief environmental correspondent anne thompson.

>> reporter: the cargo ship "mesabi miner" rides high as it docks on lake erie. and that's not good. >> she left 8,000 tons of iron ore in minnesota, that's basically a day's work for an iron ore mine. >> reporter: iron ore destined to be steel in cars and refrigerators. but the mesabi miner can't carry a full load because once again water levels in the great lakes are too low. >> it's reducing our revenue. we carry less tons, we get paid by the ton. we don't make as much money. >> reporter: this is the 14th straight year of low water levels for the $34 billion shipping industry. this january, lakes michigan and huron hit a record low. now superior, the largest fresh water lake in the world, those three remain well below their historical averages. this ship is the size of an aircraft carrier. more than one thousand feet long. but these days, the difference between success and failure is measured in a matter of mere inches. >> we're light loading the ship

by probably about two and a half feet. >> reporter: captain paul frank says the water in st. mary's river between superior and huron determines how much his ship carries. how difficult is it to steer a ship this big when there are only nine inches to two feet of water underneath you? >> well, it's extremely difficult. >> reporter: the industry wants the army corps of engineers to do more dredging. but a noaa hydrologist says the problem is not enough rain and snow over the lakes in the winter and too much evaporation, fuelled by warmer water temperatures. >> evaporation is having a much more significant impact on the system than it used to. >> reporter: so basically, the precipitation can't keep up with the rate of evaporation? >> that's a good way to say . >> reporter: impacting boaters big and small. >> this island was totally underwater. >> reporter: russ clark runs a fishing business on michigan's west coast. now there are places he can't do. >> i think we're all hoping and confident that the water levels

are going to come back. >> and keep the great lakes a source of pleasure and profit for america. anne thompson, nbc news, toledo, ohio. we are back in a moment with the reason a lot of americans say they are driving in circles.

ignition and liftoff. liftoff of sds 7. and america's first woman astronaut. and the shuttle has cleared the tower. >> look at that grainy videotape. hard to believe it's been 30 years. but it was in fact 30 years ago today sally ride became the first american woman in space. her commander said she was selected because he said he needed a competent engineer who was cool under stress as a stanford ph.d. she fit the bill. sally ride, who by the way applied to the astronaut corps after seeing a nasa advertisement in the newspaper died last summer of pancreatic cancer. she was just 61 years old. a big reversal from chrysler tonight, agreeing to recall more

than 2.7 older model jeeps and cherokees over concerns about fire risk. after first refusing a government request to do this. chrysler had maintained the popular 4 by 4's were safe. they now say calls from concerned jeep owners played a part in their decision to go ahead and comply with this recall request. we have put a full list of the recalled vehicles on our website well, confirmation of what a lot of drivers already know. that voice in your dashboard will sometimes get you lost. 63% of u.s. drivers say gps has in fact led them astray. a lot of older folks complain that their kids who have been raised on gps never did learn how to read maps. not surprisingly, drivers aged 55-plus are the most likely demographic in this country to carry a map or an atlas in the car, just in case that voice in the car is wrong. when we come back, a new

breed of visitors from home as more and more hospitals are deciding it's just what the doctor ordered.

finally here tonight, we've seen a growing number of hospitals of late trying to loosen the rules and change their ways, especially when they learn of genuine solutions that

might help their patients heal up faster. we have a report tonight on the latest attempt at this. it's about allowing your best friend to stay with you at the hospital. our story tonight from nbc's stephanie gosk. >> reporter: 15-year-old kyle wilkerson is spending the summer with his constant companion, his 100-pound chocolate lab reese. it's been a tough year for this teenager, in the hospital more than two months, and recovering from a heart transplant. carl's cardiologist was concerned. >> he was critically sick. >> reporter: that's when reverend susan roy told kyle's family about a program called faithful friends, which allows a patient's own pet to visit them in the hospital. >> so when we witness patients who are reunited with their own pets, it's really incredible. >> reporter: the reunion made an enormous impact. >> his blood pressure got a little better. we actually saw some physical, physical things that we could

really on. he got so much happier. >> reporter: the university of maryland medical center is just one of a growing number of hospitals and hospice programs across the country allowing pet dogs and cats to visit their bed-bound humans. the animals must go through rigorous screening, grooming and vaccinations to ensure safety for patients and others in the hospital. >> get the sleepies out of your eyes. >> reporter: kyle's mother denise says the visits were a turning point for her son. >> she jumped up on his bed and got real close like she was going to lick him and kind of slowed down. almost like she knew he was sick. you saw his face light up. you saw his eyes smile. >> reporter: for people with pets, particularly with dogs, that reaction isn't surprising. the american heart association says owning a dog may help reduce stress levels, cardiovascular risks and obesity. kyle's on the mend now, thanks in part to this special connection, lifting spirits and helping the healing. stephanie gosk, nbc news new york.

>> that's our broadcast on a tuesday night. thank you for being here with us. i'm brian williams. we hope to see you right back here tomorrow evening. good night. good evening everyone. i'm janelle wang and i'm raj mathai. more ethical questions involving the president of the california public utilities commission. for the deadly san bruno explosion. he just accepted a safety award for the union's representing pg and e employees. tony kovaleski was in sacramento for the awards presentation. this has been ongoing and mr. peavy's objectivity.

>> yes, it has, raj. it certainly raises more questions. the president has faced accusations of getting too cozy with utilities he regulates. now, a safety award. that just doesn't sit well with at least one san bruno resident. >>. >> a special presentation will be made to michael peavy, president of the california public utility commission. >> renee morales daughter jessica was one of the eight people killed in the san bruno explosion. >> in his tireless work on systems rye liability and safety. >> she's reading the formal invitation, a reception for legislators honoring the safety record of puc president michael peeve ee. >> i find it appalling that he's receiving an award for anything relating to safety. >> in fact, this confidential internal document first reported by nbc bay area earlier this year found high ranking cpuc employees ti