that's nice. "nbc nightly news" is next. we'll have more local news at 6:00. we'll also have the latest on some california experts now on their way to japan to lend their expertise with the contiinnu t th therou good night. disaster, in japan. dramatic rescues and utter devastation. tonight, after natural disaster, a power plant explosion and a threat of nuclear disaster. just how dangerous is it? plus a new look at the power and fury of a tsunami. captions paid for by nbc-universal television good evening. right about now people here in japan are starting to ask themselves how much worse can things get? struck yesterday by one of the largest earthquakes ever on record entire communities

swept away under a 30 foot high tsunami and now this. thousands forced to flee from path of a radioactive leak. it is sunday morning here in tokyo. far from the epicenter still feeling the occasional aftershock. in the disaster zone itself, along the east coast, rescue efforts have been complicated by damage to a nuclear power plant. it could potentially suffer a nuclear meltdown. and there is late word of an emergency involving a second reactor in that complex. hundreds of bodies have been spotted along the tsunami ravaged coast. it is estimated the death toll from the quake and tsunami could reach up to 1800. local news agencies report in one community alone, 9,500 people are unaccounted for. as thousands remain cut off by flood waters across a broad region. we have a lot to report here tonight. we want to start with nbc's lee cowan who has the latest. >> reporter: the first lifelines are being lowered into a sea of

mud and despair. while the rescue efforts are heroic, they're dwarfed by the sheer scale of japan's disaster. there are so many to help, but nowhere near the hands to offer. grim equation that is forcing those lucky enough to survive, into a terrible limbo. hundreds lining up for food and water that is available as shelters still trying to house the living, survivors look at the list of the dead. >> translator: iri still have people i haven't been able to contact and there are reports of a nuclear leak. and i'm concerned about their safety. >> reporter: add to it all, a nuclear accident. an explosion after the quake damaged a building housing a reactor causing a radioactive leak and the evacuation of a 12-mile radius.

officials say the leaks are decreasing and the risk of a full-scale meltdown did not appear eminent. japan's quake was the world's fifth largest on record. and the wall of water that followed -- was unrelenting -- and indiscriminate. it took everything in its path. ships once resting at anchor were tossed into the chaos including an oceanliner that has yet to be found. railcars met the same fate the whereabouts of their passengers unknown too. >> we are used to earthquakes in japan, i have experienced many in five years. but this is the first -- is it started shaking and something was different. straight away me and my co-workers realized, this is the big one. >> reporter: this is what the tsunami looked like from inside the airport at sendai. the terrified passengers watched and waited.

the japanese minister got a look at the devastation and the tsunami's raw power. engaged by the amount of real estate that it swallowed. once a bustling modern city, those yellow circles are key government buildings and hospitals. this is what it looks like now. a town replaced by a a toxic brew of mud, oil and debris. here alone, nearly 10,000 people remain unaccounted for. fires from ruptured gas and oil lines continue to burn out of control. the painful irony here is that water is everywhere, but at least a million homes have gone without any drinking water since the quake struck. millions don't have any power either. roads and bridges that need repair crews to fix it, remain

large largely unpassable. one barrier after another. rescuers and aid workers have to contend with as the flood of international assistance begins to crawl to where it is needed most. there is late word tonight that there is a second emergency in the second reactor. but it is in that same complex and it seems to be that it is a problem with the coolant malfunctions again. we don't know how that will effect evacuations underway there. >> powerful scary words, radio acttivety, nuclear meltdown. we want to talk more about that. lee cowan, thank you very much. japanese officials say they have calculated that 160 people have been exposed to radioactivity. 160,000 people have been evacuated from around two nuclear plants most from the one that suffered the explosion. more on this from nbc's anne thompson. >> reporter: of all the aftershocks, nothing frightened the world more than this. an explosion at the troubled fukushima one nuclear power plant. the japanese government declared

anatomic emergency here yesterday when the cooling systems failed, and radiation leaks were detected. now there was a real fear of a meltdown. throughout the day japanese tv reporters used diagrams and maps to help a nervous nation. the blast occurred at the unit one reactor. it destroyed the exterior building, but japanese officials say the reactor inside remained in tact. and blamed the explosion on a buildup of hydrogen. this government official said after the explosion the radiation leaking from the plant actually decreased as did the pressure inside the troubled reactor. >> i think they are being cautious with respect to how they implement their plan and being conservative and given the conditions there, i think that is wise. >> reporter: when the earthquake struck, the reactor shut down as it was supposed to. but the quake also cut off the power needed to pump water to cool the reactor's cool, and the backup power system failed. without water to cool it, the core could over heat and melt

down releasing radioactivity into the environment. tonight, the japanese utility took the unusual step of pumping sea water into the reactor to prevent a melt down. >> if you are pumping sea water into a reactor, you have decided that the consequences of not doing so are very serious. the evidence in this case is that they are worried about is significant melting of the core. >> reporter: more signs of concern. people living within the plant's evacuation zone are scanned for radiation. and the international atomic energy agency says japan is preparing to give iodine to evacuees from this plant and a nearby plant damaged in the quake. japan's nuclear safety agencies rates this as a 4 an a scale of 1 to 7. at pennsylvania's three mile island, there was a partial core meltdown but not a significant

release of radiation. japan now waits to see if it its fate is the same. anne thompson, nbc news london. >> we appreciate you being with us. the problem as we understand it, this particular reactor is around inability to cool did. they are putting sea water on it to coop the temperature. if they can't bring the temperature down, what is the worst case? >> the worst case is a meltdown which means that the fuel rods in the reactor heat to a high temperature that they actually melt together. you would see the core of the reactor turn to a mass that would burn right through the steel reactor vessel and drop into the concrete containment building surrounding that vessel. the very worst case is that that containment building, the

concrete box doesn't hold this radioactive molten mass, and the earn tire core then spews into the environment, putting radio activity into the ground, the air and the water. >> right now they are classifying this as a 4 on a scale of 0 to 7. apparently there is a scale to measure the nuclear reaction. >> yes. >> does that sound like a fair characterization. should it be higher on the scale? >> it sounded like a fair characterization a few hours ago, i say this will be a 5 very soon which is the rating we gave three-mile island. if there is an actual meltdown, this clearly goes into the category of 6. or even the chernoble incident which was a 7. it depends on how many reactors fail. as you noted, the latest news is that there is actually a third reactor. all three reactors at this daiichi facility, they are announcing that they lost the

ability to inject coolant into all of them. and they are preparing emergency measures as we speak for all of them. this is already if it stops right now, one of the worst nuclear disasters we have ever seen. >> mr. cincioni, thank you for your expertise, it was good having you on. we want to talk about the community hardest hit called sendai. it is on the northeast coast, the largest city in the path of theod tsunami. angus walker from our partner itn is there. and here's what he saw. >> reporter: what the earthquake spared, floods and fire have destroyed. smoke, hangs over sendai the city closest to the epicenter. a coastal community where people are now trying to escape the power of the sea. darkness has now fallen in sendai and for a second night running millions are without power. it is pitch black. have a look at this door the we're a few minutes away from

the coast, and the water mark shows you how high the flood was. and look at this, the force of the tsunami almost took this front door off its hinges. inside a shattered family home. on the walls, smiling family photos and a calendar. it was a day japan will never, ever forget. >> we have angus walker on the phone now from sendai, angus, the sun has been up a couple of hours. what have you seen this morning? >> reporter: although the center of sendai is largely unaffected, structurally, there are massive cues for food, supermarkets. most petrol stations, gas stations are closed. there are lines of cars waiting at stations that are still selling fuel. everyone in this region of japan is affected even if they managed to escape the damage. what we are trying to do at the moment is get out of the city to

head north, and there are cues on the roads. lots of heavy traffic of people trying to get away. 250,000 people are now in temporary housing. 170,000 people have been evacuated, from those exclusion zones around the nuclear reactor that you were just discussing. >> and in terms of the area, how big an area is being affected by that and is it hampering the rescuers from getting in? >> reporter: rescuers are able to get in by helicopter. we arrived at an airport yesterday, south of here. it was very busy helicopter traffic there. we have seen a number of military helicopters in the air. i went to the crisis center, city hall in the center of sendai and saw lines of military jeeps lined up. we saw red cross units. it was the size of city hall in a small town.

difficult to see how building of that size and from the number of people, i don't see how they will be able to dope with a disaster on this scale. >> all right. angus walker in sendai for us. thank you for your coverage for us. as you noted, the japanese military is bringing in military supplies. but this is truly an international effort. with a huge contingent of americans now adding to the rescue efforts. we have more from nbc's miguel al al almaguer. >> reporter: at u.s. military facilities in japan, relief efforts are underway. 1,500 pounds of rice and bread loaded onto sea hawk helicopters. the desperately needed food air lifted to cities crippled by the quake. at sea, the uss blue ridge is on the way. loaded with supplies the carrier left singapore friday. >> we are here to help the japanese people. >> reporter: with japan in a state of emergency, more help is coming from around the world. search and rescue teams from 45

countries are ready to respond. south korea, australia and the united kingdom have all deployed search teams and time is working against them. >> we know there are miracles survivors days after an incident like this. but we know the longer time goes on, the less likely it is that we will find survivors. >> in fairfax, virginia, teams loaded supplies. tomorrow they'll join a feel from los angeles in japan. it was that same crew that pulled a woman in haiti from the rubble of port-au-prince six days after the devastating earthquake there. her story inspired a country. the team will be looking for another miracle this time in japan, where some 10,000 may still be missing. >> to me, it is the right thing to do. as a member of the international search and rescue community. >> reporter: just back from new zealand the los angeles team worked side-by-side with a team

from japan. now the japanese team is headed home to a disaster that hits home like nothing they have ever seen before. miguel almaguer, nbc news, japan. >> for more on the relief effort and how you can help, go to our website. nightly.msnbc.com. when "nbc nightly news" continues here from tokyo, a question about what we are learning about the power of the tsunami.

good news in the disaster here in japan, it's the thought that this could have been much worse. this is a country that spends time preparing for disasters with constant drills and disaster exercises. it is likely that those drills saved thousands of lives. we get more on that now from nbc's indicate snow. >> reporter: japan invented the word "tsunami". it means harbor wave. tsunamis and earthquakes are not a rare occurrence here and after the kobe quake in 1995, the country went to great lengths to upgrade its building codes. in tokyo you could see skyscrapers swaying is that good? >> yes. that is good. they are absorbing the energy from the earthquake. >> reporter: they are built to sway? >> yes.

some of them have big giant counter weights at the top so that when the building moves, when it moves in one direction, it can move in another direction. [ sirens ] >> reporter: you hear sirens. it sounds like a tsunami warning. >> it is like a tornado warning that we have here. that is great. japan has developed not only better building codes, but they have better warning systems. they have buoys that alert them to the fact that we're going to have a tsunami. >> reporter: there are flood watches and drills that teach people what to do. >> there are people up there. >> they are doing the right thing. they are up on the ridge, watching what's going on down below. they have smart. >> reporter: they probably heard the warning. >> that is right. they did what they needed to do. >> reporter: but no amount of planning can prepare a country for something like this. how fast is that water moving? >> 40 or 50 miles-an-hour. >> reporter: >> reporter: if you're looking at it from the ground we're way

above. >> no, that is moving. you will look at it and see it rolling at you and hear it. it is a huge roar. it is very terrifying. the debris can pulverize you. >> the debris is harsh. >> the current can rip things apart. even a small, small amount of water, i mean, you know, something that three or four inches deep, can sweep a car. >> reporter: and there are people down there. look closely, and you can almost see the panic as it unfolds. >> like see, he's going to get caught. >> reporter: up in the right-hand part of your screen? >> yes. see how the water is coming down? they got caught. >> reporter: it is difficult to watch. but it is also worth remembering that this is a developed nation. this is not haiti with it's shoddy construction. with advanced building codes and so much awareness of earthquakes and tsunamis, the hope at this hour is that many thousands of

people were able to get to higher ground. >> kate snow, for us in new york. and kate is going to be back in a moment with some of the other news headlines of this day including a horrific bus crash in new york that has left more than a dozen people dead tonight. we will be back.

back in new york now with other news of the day. new questions about a terrible bus crash this morning in new york city. a tour bus returning to new york's chinatown from a casino in connecticut hit a sign post was sliced in two and overturned. 14 people are confirmed dead. everyone else on the bus was hurt. seven of them critically. the driver told police he lost control trying to avoid hitting a truck.

tonight law enforcement reports that passengers felt the bus swerving before the crash. they are looking into whether the driver was distracted or fell asleep at the wheel. up and down the east coast, major flooding forced people from their homes. some parts of patterson, new jersey are underwater after the passaic river spilled over its banks. bridges connecting two parts of that town are now shut down and the mayor is threatening to forcibly remove anyone not evacuating voluntarily. it is now official the standoff between national football league owners and players has resulted in a player lockout. negotiations broke off yesterday hours before the current contract expired. and a reminder, before you go to bed tonight, turn your clocks ahead one hour. daylight saving time begins at 2:00 am for most of the country. yes, that means an hour less sleep but a welcome extra hour of sunlight tom. lester has more front japan right after this.

we're back now in tokyo. people around the world have been glued in front of tv's and computers looking at the clips of when the ground here shook and the water surged ashore. some of the pictures have been horrendous and others inspiring. here now a look at the images in japan. in the hardest hit corner of japan, survival.

in the middle of so much destruction and loss, hope. a group of kindergartners rescued, stranded aboard a boat. now back on land. treating their injuries on the spot. today, growing worries about those who hadn't been found. lists of evacuees were posted at local shelters. >> my husband hasn't come here yet. he left home a little later than me. our house was swept away. >> on the roof of one hospital the staff used towels and sheets to spell out a simple desperate plea. 300 people help. and elsewhere, a young woman says she's glad to be alive. >> we are all right. i'm relieved that my baby was not harmed. >> and that is nbc "nbc nightly news" for this saturday night.

i'm lester holt reporting from tokyo japan. i will see you back here tomorrow, on "today". thank you for watching everyone. and good night. -- captions by vitac -- www.vitac.com good evening. i'm diane dwyer. we begin with more fallout from the magnitude 8.9 earthquake and tsunami in japan. tonight another reactor has lost