we'll continue to follow all the traffic updates over the next couple of days. we'll be back at 6:00. >> see you then. n the broadcast tonight, the strongest case yet for a strike on syria. the obama administration tonight calling president assad a thug and a murderer for chemical attacks on his own people. secretary of state john kerry laying out the intelligence for a war-fatigued nation. a war-fatigued nation. >> some cite the risk of doing things. but we need to ask what is the risk of doing nothing? >> tonight, u.s. warships are in position. will the president give the order to strike? "nightly news" begins now. good evening. i'm lester holt in for brian tonight. the words and the signals

couldn't be clearer. it is virtually certain tonight the united states will not let syria's alleged use of chemical weapons go unpunished. the president today said he has not made a final decision in the course of action, but the case for a u.s. military attack was spelled out in no uncertain terms by secretary of state john kerry. like a prosecutor making an impassioned closing argument to a jury, kerry today made a point-by-point assessment of the evidence against syria, and warning of the consequences should the world turn a blind eye. kerry offered new details of the chemical attacks and the assad government's involvement based on evidence he said was clear and compelling. he said any u.s. response would be limited in its scope, without american boots on the ground. and he revealed that more than 1400 people had been killed in the chemical attack, including more than 400 children. here is how the secretary of state laid it out for us today. >> our intelligence community has carefully reviewed and

rereviewed information regarding this attack. and i will tell you it has done so more than mindful of the iraq experience. we will not repeat that moment. we know that the assad regime has the largest chemical weapons program in the entire middle east. we know that the regime has used those weapons multiple times this year. we know that the syrian regime elements were told to prepare for the attack by putting on gas masks and taking precautions associated with chemical weapons. we know that these were specific instructions. we know rockets came only from regime-controlled areas and went only to opposition-controlled or contested neighborhoods. the united states government now knows that at least 1,429

syrians were killed in this attack, including at least 426 children. this is the indiscriminate, inconceivable horror of chemical weapons. this is what assad did to his own people. it matters because if we choose to live in a world where a thug and a murderer like bashar al assad can gas thousands of his own people with impunity, even after the united states and our allies said no, and then the world does nothing about it, there will be no end to the test of our resolve and the dangers that will flow from those others who believe that they can do as they will. now, we know that after a decade of conflict, the american people are tired of war. believe me, i am too.

but fatigue does not absolve us of our responsibility, and history would judge us all extraordinarily harshly if we turned a blind eye to a dictator's wanton use of weapons of mass destruction against all warnings, against all common understanding of decency. these things we do know. >> secretary of state kerry in some of his bold case for military action in syria. our reporting team is in place tonight. first to nbc's chief foreign affairs correspondent and andrea mitchell in our washington newsroom. andrea, after that speech, is there any turning back? >> reporter: no, there is not. before kerry's speech he was at the white house with the president, the other national security advisers talking about the intelligence. and they say this is what is different, the scale of the attack, the incredible number of casualties you just saw. second, the size of the target area. this intelligence map shows 12 separate locations that were hit.

it is a highly coordinated attack. and third, they had spy satellites tracking the rockets from government launchers to where they landed. finally, they say assad's command and control was established from those intercepted communications you heard about revealing they've prepared to use chemicals. they told their own commanders to put on gas masks the day of the attack, and command ers a senior official is overheard telling troops to hide the evidence afterwards from the u.n. with all of that, they say, if this president did not act, it would just be inviting assad and others to again use chemicals. >> andrea mitchell. thank you. shortly after secretary kerry made those impassioned remarks, we heard from the president at about syria during a meeting at the white house with baltic leaders. >> part of our obligation and a a leader in the world is making sure that when you have a regime that is willing to use weapons that are prohibited by

international norms on their own people, including children, that they are held to account. >> the president earlier today further indication the u.s. is preparing to strike. though he emphasized any action would not involve u.s. troops on the ground. for the latest in what it would involve, we want to go to nbc's jim miklaszewski at the pentagon. jim, what are you hearing at this hour? >> lester, the president hasn't made a decision, but a final war plan is in place, and u.s. military forces are ready to pull the trigger. five guided missiles already in the mediterranean. each armed with up to 50 tomahawk cruise missiles. the primary target, command centers for syria's chemical weapons and their delivery system. rockets, artillery and airplanes. and tonight the amphibious ship san antonio with 300 marines on board arrived in the eastern med on standby for any possible emergencies. and while no final decisions have been made, the preplanning

for this operation is so far along that once the president gives the order, missiles could be in the air within minutes. lester? >> all right, jim. let go inside syria now. u.n. weapons inspectors scheduled to leave there tomorrow. people are bracing for a possible military strike as we hear tonight from bill neely in damascus. >> reporter: all day here in damascus, the sounds of explosions, as syria's army keeps up its assault on rebels in the suburbs. but they are braced here for explosions of a quite different kind, waiting for a u.s. military strike as u.n. chemical weapons inspectors end their mission here. u.n. weapons inspectors set off to try to prove chemical weapons were used in syria. a mission governments around the world are watching. but they went today not to the site of the attacks to talk to those who had been targeted but to a syrian army hospital to interview soldiers.

syria's government says the soldiers were victims of poison gases. as ever, the inspectors gave little away. why are you here? >> because of our investigation. >> reporter: they brought in medical equipment to take samples and took statements from at least five soldiers. the syrians refuse to allow journalists to talk to the troops. the inspectors will decide if a chemical attack happened here, but not who did it. they've spent three days in the homes and streets where hundreds died and thousands were affected by what was clearly an extraordinary artillery barrage last week. the u.s. and many allies are convinced syria's army was responsible. the government here blames rebels. on the capital streets today, they are waiting for retaliation from the united states. today, all day, the smoke and

noise of explosions in damascus. syria's army shelling suburbs ready, too, for retaliation. so damascus tonight is tense. people here fearful, waiting for another twist in this two-year war. all eyes even here now on washington. back to you, lester. >> all right, bill neely in damascus. tonight there are indications that president assad is undeterred by talks of a strike. disturbing new reports of yet another atrocity, this one earlier this week against syrian civilians at a school. and a warning once again. the pictures are difficult to watch. nbc's chief foreign correspondent richard engel spoke with eyewitnesses, doctors who treated the wounded. he joins us again tonight from the syrian border. richard? >> reporter: good evening, lester. the bbc was profiling two british doctors, volunteers, they've come to syria to try to help out. they ended up witnessing a horrific attack against

civilians. and as you said, these images are very disturbing. their pain was almost indescribable. flesh burned and peeling as they staggered into a hospital. >> just for a few seconds, he was sort of look around thinking what on earth is going on? it felt so apocalyptic in a way. >> reporter: dr. rula. she asked us not to use her last name, was at a clinic near aleppo when she says a syrian government plane dropped something like napalm on a school. >> i mean, they're all children, they were all below 18-years-old. they're all kids. they were just petrified. >> there was one boy i wouldn't forget. the only sign of life he had if you like was his eyes. >> reporter: she was the only other volunteer doctor. she told us the most severely injured barely screamed. they just trembled like 15-year-old ahmed.

>> he was being patient. i probably would be foul. >> reporter: the medics supplied a white cream to cool the skin. >> i didn't think that i'd be looking after and seeing such sights, involving civilians, involving children. >> reporter: incendiary weapons are generally not considered chemical weapons, but they are not intended to be used against civilians. >> i finding the words in english. i felt ashamed, but i couldn't speak to them in arabic. >> one of the girls, she was 16 years old. and when i went to see her later, her mom was wailing next to her, and she told her mom to be quiet. and she sort of took a deep breath and looked at me and just said "do you think my face is going to be mutilated?"

i said i don't know. i hope not. >> reporter: dr. rula told us that girl was studying at the school because she wanted to be a doctor, like her. richard? >> richard engel from turkey tonight, thank you. as the administration lays out the intelligence for a limited strike in syria, we have a new nbc news poll on syria, showing americans are split on how the nation should respond. chuck todd joins us now from the white house with more on that. good evening, chuck. >> reporter: good evening, lester. it's a divided and skeptical public on the idea of using military force. we found a majority against using military action against syria. 50% being against it. but when told that the military strike would only be cruise missiles, you saw a slight change where a majority then would favor that kind of action. now, there is no ambiguity from the public when it comes to how the president, when the president should go about doing this. nearly 80% believe he should wait until congress approves whether or not to do a military

strike before he goes it alone on that front. and speaking of the president, lester, his approval rating when it comes to the issue of syria is not good at all. overall it's not great. but on the issue of syria, just 35% approve of how he's handled this crisis so far,less. it just tells you he's still got a lot of explaining to do to the american public. >> chuck todd in the white house, thanks. there are a lot of questions tonight on what a u.s. strike on syria might involve and some of the risks involved. for more on that, let's bring in retired armey medal of honor recipient, nbc news analyst jack jacobs. thank you for being here, jack. the administration laid out a moral justification for acting. in pure practical terms, what might be the advice the president is getting from generals about the downside to all this? >> well, when asked whether or not they're going to attack on these limited objectives, the answer is going to be of course we can. but they probably also offered the following advice. it is not going to depose assad,

and it's not going to make him stop killing syrians. as a matter of fact, it may encourage him to view his being in a situation where he'll increase the attacks on his own people. i think their judgment will be that it has no strategic objective other than fulfilling the requirement that we said we were going to do it, so now we're going to do it. >> jack jacobs, i appreciate your analysis. thank you. when we come back, more on the potential risks of a strike. we'll talk with a man who until recently ran the pentagon. also, that huge fire in the west that is having a huge impact on this last big weekend of summer.

with the u.s. poised to punish syria over its use of chemical weapons without broad international support, former cia director leon panetta is telling nbc the u.s. must act, saying its credibility is at stake. i spoke with panetta this afternoon about justification for any punitive attack. we have seen this movie before, the presentation of evidence of weapons of mass destruction. we know how iraq ended up. are you firmly committed to this intelligence? do you buy it? >> i do. i think the intelligence here is pretty clear. i recognize that the american people are exhausted by war. we all are. but at the same time, we continue to have a responsibility to exercise leadership in the world. it would be nice if the u.n. acted. it would be nice if our allies acted. it would be nice if others were

willing to take that action. but when that line has been drawn and action needs to be taken, then the united states ultimately has to do that for the sake of the world and for the sake of world peace. >> what's the best outcome of a u.s. military strike, in your view? >> if we do a limited and targeted attack that goes after his capabilities and that deters him from any further use that it hopefully can set the groundwork to be able to pursue a diplomatic strategy that ultimately can result in a negotiated settlement there. >> so what's the worst possible outcome of an attack in your view? >> i think the key here is to be able to make sure that the targets that we're going after are there. the intelligence is accurate with regards to where those targets are and that we do an effective job of being able to destroy those targets. that's going to be a key. and if for any reason we fail to do that, then we're going to

have to go back and make sure we do it. that's going to be the biggest challenge. >> former defense secretary leon panetta acknowledging that a first round of strikes may not be enough. our entire conversation can be found on our website tonight. we are back in a moment with some of the day's other news, including the loss of a literary legend.

in california tonight, the massive wildfire burning in and around yosemite national park has now charred hundreds of thousands of acres. while the park is opened to visitors this labor day weekend. the fires and smoke have forced road and bridge closings, and tourists-dependent businesses are feeling the heat. nbc's miguel almaguer is in tall with may city tonight. >> reporter: 30 miles from where the rim fire chews through forest land tonight, the historic town is safe but not out of danger.

this community, a doorstep to yosemite national park, is usually packed with tourists on labor day weekend. but today, lakes, beaches and businesses are deserted. the hotel charlotte is empty, but the cancellation book is filling up. >> we've had over 130 cancellations here since the beginning of the fire. >> reporter: with road blocks shutting down access to rivers, steven welsh worries his rafting business may go under. >> probably 15 or 20% of our season was lost to the fires. >> reporter: still, these ladies were determined not to cancel a long-planned trip. >> the fire and smoke is not going to prevent us from doing anything. it's just fine. it's beautiful up here. >> reporter: but the nearby fire is massive, growing as much as 3,000 acres an hour some days, the blaze is now up to over 200,000 acres, larger than the cities of san jose, san francisco, and oakland combined.

even though it's a holiday, you work around the clock? >> we work around the clock, seven days a week until this thing is put out. >> reporter: hopscotching through the wilderness, the impact of the rim fire can be seen and felt hundreds of miles away, taking more than just land. now threatening tourism on this holiday weekend. miguel almaguer, nbc news, outside yosemite national park. >> the celebrated irish poet seamus heaney has died. he won the nobel prize for literature in 1995, the third irishman to do so along with yates and samuel beckett. his publishing company says heaney died today at a hospital in dublin. he was 74. the duchess of cambridge made a surprise public appearance today alongside her husband, greeting the participants at the embassy ultra marathon, her first official event since giving birth back in july. baby george stayed at home. it was all part of the royal couple's tour to say goodbye to the island off the coast of wales where they have lived since 2009. they'll be soon moving back to

london. we're back in a moment with some final thoughts after a whirlwind few weeks.

>> tonight as millions of americans ease into the last

days of summer, we find ourselves in an uncomfortably familiar place. we have been here before as a nation, wondering if american forces are about to begin an attack in some far-flung corner of the world. this time would be syria. and no matter how and when the u.s. opts to respond, there will be strong reaction. our team is in place and will be closely monitoring this situation all weekend long. i'll see you a bit later on dateline, and tomorrow morning on syria on "today", and a reminder, brian will be in this chair on tuesday. it's been a real pleasure being here this month. i'm lester holt in new york. for all of us on nbc news, good night.

nbc bay area news starts now. and right now, at 6:00, navigating around the bay bridge closure, a live look from our chopper over the san mateo bridge. take a look at that eastbound traffic. it is moving slowly, but far, far better than it was just a few hours ago. want to give you a live look at traffic around the bay area. you're looking at the golden gate bridge right now. and traffic is moving smoothly, especially for a friday night. let's take you over to

interstate 880 in oakland. not bad. maybe lots of people left early. some green on that green. some yellow. but mostly green. a lot of people trying to move home quickly. there is some traffic around the peninsula and the east bay though. so when will the bridge open on time, for the $6 billion question, we turn to jodi hernandez, live at the bay bridge toll plaza with more on the progress of construction crews there. >> reporter: and they're making a lot of progress. cal tran says they will be 40% done with this project. and by our calculations, if they continue with that pace, they will be finished ahead of schedule. as you can see, they have finished paving all the way up to the toll plaza. and now crews are working on striping the lanes. this project is definitely on the fast trk.