at sfo tonight at 6:00. see you then. good night. on this sunday night, the investigation into the crash of asiana flight 214. the first readout from the black box is revealing a plane making its landing approach far slower than planned. and the crews' last second effort to avoid impact. >> i was trying. >> as passengers share their harrowing survival stories. search and rescue in a devastated town. dozens of people still missing after a deadly train explosion. we're there with the latest. severe weather, millions coping with excessive heat and flash flooding. and finally, the road is over. andy murray becomes the first british man to win at wimbledon in decades.

good evening. federal air safety investigators in san francisco tonight are revealing early but important findings in their search of the cause of crash of asiana flight 214. the black box recordings from the ill fated flight now focusing questions on the crew and its last ditch attempt to abort the landing as an alarm began sounding. two chinese teenagers died yesterday when the boeing 777 struck a seawall and broke up bursting into flames. tonight as many of the injured remain hospitalized, passengers are telling their riveting stories of escape and survival. once again we are covering all angles of the story. we want to begin at san francisco's international airport and john yang.

>> reporter: good evening. the cockpit voice recorder, that black box that records all the sounds in a cockpit including crew conversations is giving investigators a pretty good idea of why this big jet came up short when it tried to land. tonight, key clues about the final moments of asian flight 214 revealed. recordings of cockpit conversations seem to show that the crew thought everything was fine until about seven seconds before landing when one crew member calls for increased speed. then three seconds later they get a warning that the plane is about to stall, lose its ability to fly. a second and a half before impact a call to abort the landing, but it's too late. >> the approach speed was 137 knots. and the question was whether or not we had the lowest speed that the crew achieved. i will tell you that the speed

was significantly below 137 knots and we're not talking about a few knots. >> reporter: national transportation safety board investigators recovered the cockpit and flight data recorders and sent them to washington overnight. they also inspected the wreckage inside and out. the boeing 777 was ending a 10 1/2 hour flight from seoul, south korea on its final approach to run way 28 left over san francisco bay when one crew member sensed something was wrong. >> i was looking in the window and i was just looking. and i could realize we were too low. basically it sound like we were about to land in the water. >> reporter: witnesses said the plane's tail hit the seawall. the rest of the fuselage slammed down on the pavement and breaking off a piece of the landing gear. officials say that when the tail broke off, two passengers,

16-year-old girls from china were thrown from the plane and killed. they were part of a middle school group coming to a summer camp. once the plane came to rest, survivors began their evacuation. a scene described by the pilot of another flight. >> we see people and i think they need immediate attention because they are alive and walking around. >> he said he saw people were just walking outside the airplane right now. >> yes. >> roger, we have emergency vehicle responding. >> reporter: a veteran pilot says the plane seems to have come in too low and too slow. and that for whatever reason the pilot didn't or couldn't correct it. >> at some point the aircraft begins to settle settle and the pilot will immediately pick up on that. and if he's close to the run way, there's no time to recover. >> reporter: investigators still have to corroborate what they heard in these conversation. but this could be a big piece of

the puzzle. >> we want to turn now to the passengers who survived flight 214 and their harrowing stories of survival. nbc has been speaking to some of them as well as the doctors treating them. miguel, good evening. >> reporter: good evening. tonight many of the survivors are hospitalized here at san francisco general. six are in critical condition including one child. but incredibly, many have been treated and released. amid the smoking wreckage on runway 28 left, amazing stories of survival. >> i was holding thing so tight, and bang. the impact was so powerful. >> reporter: eugene rah was sitting in row three. his perspective from the front row of the plane -- >> i felt, you know, i was dying. that was the moment. >> reporter: he remembers the fear in the air as the plane touched down. but tonight he's still haunted by the silence after the crash. >> nobody was moving. no sound, nothing. >> reporter: but the silence

didn't last long. >> it was disbelief, screaming. >> reporter: ben levy says the cabin began to fill with smoke. he was sitting in an exit row by the right wing. he considers himself one of the lucky ones. >> my injuries are bruised ribs and -- torn ligaments inside. >> reporter: levy helped many of his fellow passengers off the plane and on to the emergency slide. from the tarmac he could see the flames engulf the plane. >> in your head everything goes in slow motion, you just don't believe it's happening. you don't know if you're going to be dead at the end or not. >> reporter: the survivors, some dazed other severely injured, 53 arrived at san francisco general. >> the most serious injuries were the combination of abdominal injuries, head injuries, spine injuries, injuries to extremitieextremiti >> reporter: it was packed with student from china.

this young girl was traveling from china. >> when the flight crashed i just grabbed my son. >> reporter: tonight her 4-year-old son is recovering here at san francisco general where doctors say it is a miracle so many could have survived. the staff remains optimistic, but point out those who are still hospitalized tonight have a long road ahead of them. >> thank you. former ntsb investigator is with us tonight. the early read from the voice and data recorders were the ingins were performing fine, the flaps were set. yet this plane somehow slips far below the approach speed. what are your thoughts? >> that's going to be a big question that needs to be answered. the board has to verify that that was the correct speed for the weight. but then they have to find out why the crew didn't monitor that speed and see that it was falling below their target earlier than they did.

it's apparent that one of the crew members said increase your speed. but by then the accident sequence was already happening. and by the time they reacted and pushed the power up, the airplane settled into the ground. >> back me up a second. i know planes have auto throttle. is this the case where that would have been controlling the speed or would the pilots have positive control? >> it's a combination of both. that's what the board is going to have to ferret out is were they using part of the automation or a lot of the automation during the approach. and even if they do use the automation, they monitor it. they have their hands on the throttles. they are having their hands on the control yoke, as well. they're basically shadowing what the automation is doing. if there's something wrong, they then disconnect the automation and then hand fly the airplane. they're going to want to know why the corrective action was so untimely before the impact. >> greg feith good to talk to you again. >> now to the search and rescue across the u.s. border after yesterday's deadly oil train explosion in quebec.

a fire chief has compared the devastation to that scene in a war zone. dozens are missing and people are fearing the worst tonight. katie, good evening. >> reporter: good evening. the death toll now stands at five but that could be deceptively low as investigators have not been able to get to the heart of the crash. viewed from above, it looks like the aftermath of a bomb. a run away tanker train filled with crude oil derailed and exploded in the heart of this town saturday morning sending up a massive fire ball and flattened buildings. >> we heard a big sound, a very big sound, and we see the train coming very fast. we see it a few seconds. and then there was explosion. >> one after another, the blast lasted for hours forcing 2,000

to evacuate the once bustling downtown area. as of now 40 people still unaccounted for. >> everybody knows at least one person who is dead or missing. >> reporter: this morning, more than 32 hours after the accident, the fires were still burning. and the recovery effort stalled. fears of just what investigators will find. >> for security reasons weave only got the areas that are cleared that we can go in. >> reporter: this afternoon concerned about local waters. as oil and flame retardant slick the surface. right now no official cause of the crash. but a spokesman tells nbc news an engineer had parked the train about seven mile outside of the town for an overnight driver's shift change. then during the night the fuel cars somehow detached from the train's locomotives and rolled downill into the town derailing and then exploding.

today as prime minister toured the town local reporters asked him about growing anger towards the rail company. >> i understand emotions here on the subject are very high. you know, the information that i've seen about what has transpired, it may not be complete, but it is very, very concerning about why this occurred with that all said, there are proper authorities to investigate this. >> reporter: now back out here live, they've been pouring water down on that scene all day long. the last two containers that were on fire have been contained. the pressure is still so high in there that it's not yet safe to approa approach. one of the reasons they're so concerned about the death toll going higher, there's a popular nightclub and it happened at 1:00 a.m. on a saturday morning. so investigators aren't quite sure what they are going to find down there. >> thank you. turning overseas to the crisis in egypt where supporters and opponents of morsi took to the streets again today.

morsi is still under house arrest and the state department is watching and waiting for the military generals who deposed him to fill the leadership gap. amon is in cairo tonight. >> reporter: egypt's military is scrambling to get a government in place and tonight we are learning who may lead it. meanwhile the supporters and opponents of the ousted president have continued their demonstrators. hundreds of thousands of supporters of morsi and his opponent demonstrated in rival marches across the country. those demonstrations have at times turned violent as the two sides have engaged in running street fights. the man who was widely expected to be the interim prime minister told us that he was expected to be pointed as the prime minister. but some of the country's political parties objected to him so instead he's likely to become the interim vice president. the man who is expected to be the prime minister, is a well

respected economist and lawyer. many hope with his economic background, he be able to address their economic woes. one thing protesters on both sides agree on is their anger with the united states. morsi supporters say the u.s. is backing this coup against an elected president while supporters say the u.s. has been supporting the muslim brotherhood for the past year. this evening a spokesman told us that while the president has been meeting with various political forces he's expected to make an announcement tomorrow. and many hope here it will calm tensions on the streets. >> thank you. there's late word from nantucket, massachusetts tonight that mrs. kerry, wife of john kerry was taken by ambulance and admitted to a hospital in critical but stable condition.

she is a long time environmentalal activist and head of the heinz family foundation. she's 74 and a survivor of breast cancer. no word as to why she was hospitalized this evening. when nbc nightly news continue on this sunday, what aviation experts want you to know in the event of a plane crash, why so many crashes are survivable if you know what to do. and from suffocating heat and humidity and drenching rains and what's causing this extreme weather?

now to pressing concerns over passenger safety in the wake of the asiana airlines jet crash. while there was a tragic loss of life, aviation investigators are also pointing how many were able to escape. nbc's tom costello recently visited the center about

surviving a crash. >> reporter: investigators say that the fact that so many people survived this says a lot about how modern aircraft are built. seats are made to absorb much of a sudden impact so passengers aren't catapulted through the plane. interior carpeting and fabrics fire resistant to allow people more time to get out. it's working. everyone survived this american airlines plane crash in 2009, the continental crash in denver in 2008. and the crash landing in toronto in 2005. and no fatalities during the miracle on the hudson in 2009. getting out alive usually comes down to seconds. here in oklahoma city, they recreate plane crashes to study what it takes to survive. once the plane comes to a rest time is of the essence. at 30 seconds, smoke can start filling the body of the plane.

as fire starts eating into the fuseolog. at 60 seconds, the burning plastics, fuel, fabrics, can all turn this smoke toxic. getting out is critical. at two minutes there's now a serious risk of a flashover and fire engulfing the entire cabin. getting out is a matter of life or death. >> you want to stay low with your head below the tops and see backs. use your armrests for support. and come to the colored lights which mean your at the exit. >> reporter: leave your carry on luggage behind. during the miracle on the hudson while passengers passed babies one passenger insisted opposite grabbing her personal belongings during the miracle on the hudson. >> one lady had her coat and several bags. she lost it all anyway. >> leave it behind and get off the airplane as quickly as you can. >> reporter: as investigators look at what went wrong in san francisco they will also assess what went right. >> when we come back, some of

the day's other headlines. including the wave of shootings in chicago over this holiday weekend.

a solemn process began today for the 19 fallen firefighters who lost their lives battling a fast moving wildfire in central arizona. their remains draped in american flags are being transported from phoenix to prescott where they'll be memorialized on tuesday. they belonged to the skilled fire suppression team known as the granite mountain hot shots. from fires to flash flood flooding and heat and humidity. some suppressive weather conditions. nbc david gutierrez on the battle against the elements. >> from the mid-atlantic up to new england, excessive heat warnings are in effect for millions of people

throughout philadelphia and new york. where more than 400 cooling centers will open on monday. in oklahoma at a concert meant to raise money for tornado victims. >> hot. really hot. >> reporter: almost 1300 people were treated for heat related problems. 21 went to the hospital. at least two of them in critical condition. ohio and kentucky had a different problem. fast moving rained flooded rains in the lexington area. near chattanooga, a roof collapsed. and around daytona beach, florida rip currents have forced more than 100 water rescues since thursday. >> red flag conditions throughout the weekend which mean very hazardous. >> reporter: in the west, the heat is fueling at least 18 major wild fires including this one in nevada that has already scorched 6300 acres. and is just 30% contained. >> there's a very large swing in

the jet stream that brought extreme weather from the flooding rains all the way from the gulf coast to carolina and even into kentucky and places in the ohio valley. this is all part of a settle of weather systems that has come together in an unusual way. >> reporter: unusually wild weather that has millions on alert tonight. >> this has been a heart breaking holiday weekend in chicago. where a wave of shootings has swept that city since wednesday night. 12 people shot and killed, another 55 have been wounded. the victims ranging from a 5-year-old boy to a 72-year-old woman. police say much of the violence has been gang related. when we come back on this sunday evening, there could only be one winner in the clash of the titans. and it's got a lot of people saying, it's about time.

hail, hail, andrew the conquerer. the last time a british man won at wimbledon, the thrown belonged to wing edward viii. all of that has changed now. >> reporter: if andy murray felt the burden of expectation or an entire nation on his back, he hid it well. after 77 years without a british man's winner at wimbledon, the crowd was hungry for victory. but the pace was punishing, the rallies long, the atmosphere tense.

he drove novak djokovic to his knees. but at the end, in the final game murray lost three match points before the 26-year-old scott finally became the king of the grass court. >> the great british drought is over. >> reporter: his girlfriend seemed stun and his coach cracked a rare smile. as the new champion of wimbledon took it all in. marking the historic moment with a hug with his mom. >> it was an unbelievably tough match. so many long days. i don't know how i managed to come through that final game was unbelievable. >> reporter: the last british wimbledon winner was fred perry back in 1936. a very long time ago. it's not been much fun being a fan of british tennis for as long as anyone here can remember. but now as last there's something to celebrate. >> everybody at the end was hugging and cheering.

>> that last game was one of the most painful things i've had to watch. but as a scott, we're so happy. >> reporter: if murray's home town they went wild. now andy murray has finally made history in his own backyard. an a -- anabelle roberts, nbc news, london. >> that's nbc nightly news for this sunday. i'm lester holt reporting from new york. from all of us at nbc news, good night.

>> announcer: nbc bay area news begins with breaking news. a call from one of the crew members to increase speed was made approximately seven seconds prior to impact. >> and that was the first sign of trouble, just seven seconds before the crash from the cockpit of this airplane. right now a live picture of the wreckage at sfo. we are learning more about why the plane went down and how one of the two teenage victims may have died in the chaos that followed the crash rather than in the crash itself. good evening. i'm diane dwyer. terry mcsweeney has the night off. just into our newsroom tonight, a picture from inside the cabin. you can see the oxygen ma