from nbc news world headquarters in new york, this is "nbc nightly news" with lester holt. tonight firefighters from california to idaho are locked in a dangerous dance with the weather as they search for an opening trying to get an upper hand on wildfires. the huge blaze east of boise, idaho has stalled on the door step of one resort village and now poses an additional threat to the west. it is one of several fires raging to the american west. one of the most brutal fire seasons anybody can recall. nbc's mike joins us. >> reporter: the most dangerous threat has been just north of here.

that same fire now has other towns on high alert. as happens the shape and movements of idaho's fire have changed. when the occupants were given evacuation orders some feared the worst and vowed to stay until the very last minute. >> until i see fire come over the hill i will stay. >> this is a big investment for us. this is our retirement. >> reporter: the fire stalled two miles away leaving commander no choice but to wait before attacking the fire head on. >> it's just frustrating. that's where we are at with this fire today. >> reporter: while featherville's moment of truth is delayed the fire has spread to the west northwest. it's the weather that sets the pace.

predicted thunderstorms could dump needed moisture but that means lightning. >> the lightning could hit the ground and spark new fires cht. >> reporter: there are similar stories across the western wildfire zone. 35 dangerous fires burning in ten western states in a brutal season that has seen 6.7 million acres consumed. even while fires are on the way to being controlled those whose homes are threatened feel a similar helplessness. >> i don't have rental insurance or fire insurance. it's not good. >> reporter: so this is the strategy of choice, limit the fuel near threatened homes and then set strategic smaller fires called back burns to be sucked in by the approaching big fire but to do it at just the right time. >> they do it too early the fire will burn in the wrong direction. >> it has worked before? >> it has many times. >> reporter: now there is another western fire, the

ponderosa fire that started yesterday and threatened 3,000 more homes. here in pine, idaho the thunder and lightning have started. good news and/or bad news and no way to predict which will win out. we are far from the only country facing a tough go with wildfires this august. nasa satellite images were used to produce this global map showing a composite of wildfires detected. many are below the eequator where winter has offered no wasting. a battle to stop the deadly west nile virus. public health officials are planning to resume aerial spraying tonight against the mosquitoes that carry the west nile virus. we get the latest from janet shamlian. >> reporter: the air assault on the west nile virus will start again tonight. for days small planes have been

grounded in dallas where the virus has taken the biggest toll. >> all mosquito control operations are always weather dependent. we are going to be at the mercy of the rain and wind speeds above 10 miles per hour here on the ground. >> reporter: a third of the nation's cases are in north texas. 14 have died, hundreds are sick. experts say the numbers are certain to rise. >> it's the late summer disease. the fact that we have so many cases this early and it is so wide spread does not bode well for the future summer. >> reporter: across the country there are 693 confirmed cases in humans and 26 death. more than half were in texas which was pounded by weekend storms. >> there was slow moving storms meaning it could produce a lot of rainfall and could lead to more standing water and that is the problem because that is where mosquitoes like to go. >> reporter: now a door to door battle arming neighbors with information. >> we are passing out brochures.

>> reporter: symptoms include headache, fever and body aches and can lead to nausea, muscle weakness and paralysis. the cdc says 80% infected won't have symptoms at all. >> i am asking all faith communities to please pray for no rain and light winds. >> reporter: appealing to a higher power amid plans to relaunch the fight against west nile from the air. janet shamlian, nbc news, houston. syria's embattled president made a rare public appearance today. thousands of people staged antigovernment protests as the 17-month civil war moves on. ayman mohyeldin has the latest in turkey.

>> reporter: president assad appearing on state tv attending prayers celebrating the end of the muslim's holy month of ramadan flanked by all of the president's men except one, this man, vice president. there are reports that he has defected which is a strategic blow to president assad. in recent weeks the syrian regime has seen high level defections. indication that the biggest challenge to the regime may be coming from within. this is how the regime is fighting back to survive pounding cities and towns across the country leaving a path of destruction like here in aleppo that gave people a chance to salvage what they can. some mourn and others press on

with their demonstrations demanding the removal of president assad and the government. today the u.k. reports that british intelligence has been instrumental in providing rebels the information. while the assad regime fights on thousands of muslims are spending the festival languishing in refue gee camps in other countries. ayman mohyeldin, nbc. wiki leaks founder julian assange made his first public appearance in two months today in london where assange has been granted asylum. his message was aimed at the u.s. government. duncan golestani was there today. >> reporter: julian assange once

again stepped into the spot light. he stood tantalizingly close to the police officers waiting to arrest him but they can't, not while he is on embassy property. >> i ask president obama to do the right thing, the united states must renounce its witch-hunt against wiki leaks. >> reporter: sweden wants him but it is the u.s. government he fears. he claims the allegations of sexual assault made by swedish women are part of a plot to extradite him. bradley manning is charged with passing classified files to wiki leaks. >> he is accused. he is a hero and an example to all of us. >> reporter: with no sign of the standoff ending the diplomatic has been heating up.

the decision to give julian assange asylum was done without giving into threats. back in london assange took his moment savering the cheers from the crowd leaving everyone wondering how and when he will finally leave. duncan golestani, nbc news. in politics the candidates took a break from the campaign trail today but there was no rest for their surrogates who debated the big topics of medicare. kristen welker has the latest. >> reporter: after a week of personal attacks on the campaign trail president obama and mitt romney spent a quiet sunday morning in church. the obama's in washington dc and the romney's in new hampshire. their surrogates spent this sunday morning on talk shows. it was anything but quiet.

>> the campaign of hope and change has been one appearance here. >> this faux outrage by mitt romney complaining and whining about the tone of the race is hypocritical. >> reporter: the campaigns continue to focus on finding the issues debate in terms that will solidify their political bases. romney advisor continued to press the latest republican line of attacks on medicare. >> in order to pay for obama care he raided the medicare piggy bank. >> reporter: stephanie cutter. >> president obama strengthened medicare. >> reporter: and vice president biden's controversial remark regarding republicans wall street reform. >> going to put y'all back in change. >> saw vice president biden play the race card. >> not just that comment.

joe is a laugh line on jay leno. it is a joke. >> reporter: also on "meet the press" maryland governor says the remarks is a distraction. >> it was a play on the republican words of shackling the economy with regulations. there is not a racist bone in joe biden's body. >> reporter: political analysts say only 3% to 5% of voters are still undecided, a fact that may be driving some of the personal attacks. >> those are ways to take people who have already decided and soak their sense of anger and motivate them to vote. >> reporter: all of the candidates stayed at home today. mitt romney will resume campaigning in new hampshire on monday. todd aiken told an interviewer today that he opposes abortion even in the case of rape because if it is a legitimate rape the female body

has ways to try to shut that down. and added if it does result in a policy the punishment should be on the rapist and not attacking the child. aiken later said he misspoke and said his remarks do not reflect his deep empathy for rape victims. the obama administration finds itself in a troubling situation. it turns out iraq has been helping iran get around financial sanctions because of the nuclear program. andrea mitchell is in our washington bureau tonight with more. >> reporter: this is a delicate diplomatic and political problem. iraq's central bank -- three weeks ago president obama said the bank was facilitating millions of dollars in illegal transactions to iran.

only last week iraq's central bank sold dollars to that bank. dollars that can be used by iran to keep the economy afloat. u.s. officials tell me it is impossible to shut down normal smuggling. they don't have hard evidence of raids in the new york times. president is personally involved. this could fuel mitt romney's criticism that the obama administration has not been tough enough on iran and israel's prime minister complaint that sanctions aren't working. from afghanistan tonight there is word that another nato soldier has been killed by an afghan police officer ft that raises the coalition death toll to nine in the last 11 days. when nightly news continues extreme weather and the heavy physical toll it is taking on the country. they are being called law

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infrastructure to the breaking point. the problem, say the experts, the system simply isn't built for these record temperatures. >> roads that might have been built for 85 degree temperatures can't necessarily withstand day after day of over 100 degree temperatures. >> reporter: we have seen it in north dakota, north carolina. roads have sent traffic to a stand still. it has affected the nation's airports. this plane got stuck in melting asphalt. in wisconsin drivers who hit this buckled road were sent flying. in tennessee a parked car sank over a broken storm drain. in minnesota a flooded sink hole swallowed this driver's car. >> you don't expect the road to fall. >> reporter: in a chicago suburb two motorists were killed when a railroad bridge collapsed. in guthrie, oklahoma, another

bridge buckled while in connecticut the nuclear power plant was shut down because the sea water used to cool the plant was too warm. in washington the cleanup took weeks after hurricane force winds knocked out power to millions of customers. >> it lasted about 20 minutes and did incredible damage. >> reporter: with the power out for days on end frustration at the utility companies sored. >> why in the 21st century do we have electrical grids that are so vulnerable to mother nature? >> the big issues are trees. the trees crashed down on our infrastructure. >> reporter: experts say the entire infrastructure grid can be crippled in a flash by heat, wind or water. with extreme weather becoming the new normal many scientists are warning that the nation's utilities, bridges and roads

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the scene at boston harbor today america's oldest commissioned warship set sail. the uss constitution made a short trip to commemorate the battle 200 years ago today. that battle earned the constitution its famous nickname, old iron sides. this is the first full weekend back in the states for many american olympians who are still basking in the glow from london. one of them is gymnast gabby douglas whose two gold medals made her an overnight and bankable star. a remarkable journey she reflected on with me during a stop in new york this past week. >> it's been crazy here and there but was very fun and

energetic on the way. we had some tough times but that's what i like about it. because you can face these difficulties. >> you talk about being a role model. i heard people talk about being a role model to african american girls. i think that sells you short because you are a role model to girls if not boys, as well. >> thank you. i want to be an inspiration to everyone and tell them that anything is possible. you can do anything that you set your mind to. >> and you can see much more of our conversation and some of gabby's home movies tonight on "date line." an 80th birthday party for john williams joined at tanglewood. director steven spielburg said williams scores for his movies were the single most significant

contribution to his success as a film maker. for law enforcement they have become the top dogs.

dogs are man's best friend, one dog has risen to the top of the order when it comes to police work. kerry sanders shows us why bloodhounds have become such valuable partners. >> reporter: when katlyn was 13 years old a deputy's bloodhound found her unconscious deep in the woods. >> i don't think i would be alive if that bloodhound didn't come out there. >> reporter: bloodhounds are becoming law enforcement's best friend. >> when they find you this is what they want. >> reporter: they have become the nation's bloodhound trainers. why? angela's 26-year-old sister was abducted in indiana more than three decades ago, gone without a trace. her body was found ten weeks later. >> that ten weeks was absolute

torture. >> reporter: her murderer was never found. >> if one would have been trained at that point at that time you know we could have really done some good. there was nothing available. >> reporter: duke's son cody haunted by his aunt's murder became a deputy, his partner a bloodhound named jimmy. cody died in a motorcycle accident. >> pixy inspired cody and cody inspired us. >> reporter: over the past decade the nonprofit charity named after cody's badge, 832 has donated 140 bloodhounds to law enforcement agencies in 29 states. why bloodhounds? >> their ears are sweeping the ground causing the odor off the ground. >> reporter: the bloodhounds are often gentle and loving which

means they don't tear, don't bite and when they are looking for a missing child they often lay down next to that scared little boy or girl. bloodhounds sniffing, tracking, doing what comes naturally. kerry sanders, nbc news, florida. today the mars rover curiosity fired its laser for the first time using a beam to break apart a fist sized rock. the mission's chemistry and camera instrument hit the rock with 30 pulses of its laser during a ten second period. that's "nbc nightly news" for this sunday. i'm lester holt reporting from new york. for all of us here at nbc news, good night.