Announcer from nbc news World Headquarters in new york, this is nbc nightly news with brian williams. Good evening. A number of new theorys have emerged about what might have happened to that missing jumbo jet, gone from sight for 11 days now. The problem with all of them remains the single most tragic fact, theres no accounting for the 239 missing souls on board the aircraft. While a lot of the debate is about electronics and radar signatures and altitudes and flight paths, there remains an awful lot of area to be searched and a massive aircraft has so far managed to disappear without a trace for over a week now. We get the very latest on the investigation including some new details tonight on the crucial turn in the flight from nbcs tom costello in our d. C. Newsroom. Tom, good evening. Hi, brian. We knew that whoever planned the uturn in the plane, did so with the help of the on board computer. Tonight we learned when the turn was programmed in. At least 12 minutes before the copilot calmly said good night to the air traffic controllers. That would further indicate the you h turn was planned and executed in the cockpit before the controllers lost contact. Tonight, nbc news has learned that flight 370s uturn was manually programmed into the computer in the cockpit. That means the uturn was premeditated. Executed only the last radio call and after the transponders went dead. If the pilot entered that turn, why . Some pilots will program in an alternate flight plan in the event of an emergency. We dont know what the reason was for this time flight plan, whether to go back to kuala lumpur or to take it back from beijing. Reporter a retired captain helped recreate in a 737 what we know, someone turned off the transponder with the flip of a switch. You can see i can push the button and that would bring it up. Reporter they switched off, then disabled the acars data system, possibly by pulling the Circuit Breaker. The Circuit Breaker would be on one of these pack panels, behind the pilots. Reporter easy steps for a pilot. Total time, 20 seconds. Then making a youturn back to kuala lumpur. All i have to do is spin this knob around and the aircraft will turn around. Reporter sources tell nbc news whoever turned the plane programmed the flight Management System and knew what they were doing. This would be a very elaborate scheme. They would have had very, very extensive training to pull this off. Reporter meanwhile, the most intense search remains focused on the rough waters over the southern indian ocean. 1,500 miles southwest of perth, where a massive 370,000 square mile area simply too big for an underwater sonar search. Malaysian Authorities Say searches of the homes and even a Flight Simulator turned up nothing suspicious. Tonight with the flight crew under the microscope, the family of the captain released these images showing the man they love. And theres this, thailand today said its radar did pick up a plane that might have been flight 370 early in the morning on march 8th. Thats not surprising since the Malacca Strait borders thailand. When asked why they didnt provide the information sooner they simply said, because they werent asked. Brian . Continues to be a remarkable mystery, day 11. Tom costello starting us off from d. C. Tom, thanks. Again tonight we saw him in our setup piece, we turn to greg feith. Hes senior air safety director, a veteran pilot himself. Greg, this left turn had to be manually punched in in the cockpit, knowing what we know about you pilots, its in your blood, whether you fly a single engine or a wide body to always know where you go in case of trouble, sometimes its behind you, below you, out in front of you. Always cognizant of where to go in case of trouble. Why wouldnt this be consistent with a captain who perhaps had trouble on board . It could be, brian. We just dont have enough information. Its possible they programmed in their alternate plan. That is, if they had taken off, had a problem, all they would have to do is pull up that stand by flight plan, put it in the active window, hit execute to come back to kuala lumpur. Or they could have put in a stand by flight plan to take the plane away from beijing and return to kuala lumpur and put it in a phantom waypoint all the way down into the south indian ocean and continue to let the plane fly that direction. Thank you, well continue to let this continue. Well have more from greg, tom, our team of journalists covering this investigation their updated work on our website tonight. It will remain there at nbcnews. Com. Also making aviation news today, a local news helicopter crashed shortly after takeoff, landing on cars below, all of it right in front of the citys landmark space needle. We get our report tonight from nbcs miguel almaguer. Oh, my god. Reporter witnesses in downtown seattle could do little to help. These pictures taken moments after impact. Were responding to 400 broad street. Reporter the news helicopter plunged off the tv stations roof into the busy streets below during rush hour. Burning in the shadow of seattles iconic space needle. Only the choppers tail section was recognizable. The aircraft was lifting off the helipad at fisher plaza. Something went horribly wrong. Reporter the crew inside, an experienced pilot and long time photographer working for komo television were pronounced dead at the scene. Tonight ntsb investigators are combing through the wreckage. Were looking at everything, the environment, the weather, the pilot. Reporter one man in serious condition crawled out of this burning car. His head was bleeding, his shirt was on fire and he collapsed. Get back. Reporter construction workers tried to keep people away, as jet fuel poured through a downtown street. Stay away from the fuel, get back. Reporter the tragedy could be seen from newsroom windows where the victims worked. A horrific sight for colleagues who are now covering the news. We heard the explosion as the chopper hit the ground. Reporter tonight in seattle, answers to what caused the crash may not come for weeks. This is one of the last shots taken of the helicopter this morning, framed against a rainbow. Its hard to put into words what that image means. Reporter tonight colleagues struggle to say goodbye. Miguel almaguer, nbc news, los angeles. In moscow today, just like that, Vladimir Putin signed a document and made it official and now tonight crimea belongs to russia. Even though the u. S. Is calling this a land grab, theres nothing anyone can do about it, and the majority of local opinion seems to support it. And for the two leaders here, putin and obama of the u. S. , they now seem to be assuming public roles we havent seen since the cold war. We get our report tonight from our chief Foreign Affairs correspondent andrea mitchell. Reporter Vladimir Putin today emotional, strident, delivering his version of russian history to a cheering kremlin crowd. Accusing the u. S. Of breaking promises. Expanding nato to russias borders. Cheating over and over. And in red square, declares that crimea is finally heading home to russia. While putins deputies ridiculed the u. S. Sanctions in tweets addressed to comrade barack obama, when in crimeas capital, the exchange turned deadly. Gunmen dressed in Russian Military uniforms stormed a base, killing a ukrainian soldier, the first known casualty of the conflict. Russia seemingly oblivious to u. S. And european threats for consequences for annexing crimea. Putin is dug in, i mean, this speech today was really over the top, and in my opinion, really ends the post cold war era. Reporter flying overnight to calm ukraines neighbors, natos newest members, the Vice President sounded like a cold war era, accusing putin of a brazen land grab. Many argue putin would have gone after ukraine no matter who was in the white house. Any cooperation with russia on syria or iran . Theres no question that if we have a rupture in our relationship with russia, there are going to be costs elsewhere in the world. Reporter and there are political costs for the president at home. Every day, every moment that hes working on a Foreign Policy issue, no matter how pressing, is a moment hes not focusing on the economy, in the minds of people. And that is their number one issue. Reporter so far, the only clear political winner seems to be in moscow. Andrea mitchell, nbc news, washington. President obama told the assembled honored guests at the white house this afternoon, this is going to take a while and it did. Because today the president on behalf of a grateful nation presided over the Largest Single Group of recipients of the medal of honor since world war ii. Here are the names of the 24 recipients awarded today. In many cases they were denied the nations highest military award because of their race or religion. And of the 24, from three separate wars, only three men survived. And they stood together today. Sons and daughters accepted for the deceased heroes and for many the ceremony was overpowering, several were comforted by the president. Our report tonight from our pentagon correspondent jim miklaszewski. Reporter for 72yearold vietnam veteran, Melvin Morris, it was 44 years and coming. When president obama called with the news, morris collapsed to his knees. I was overwhelmed at that point. And he was saying, be cool, be cool, be cool. Reporter today at a highly emotional white house ceremony, president obama presented a medal of honor to 24 Service Members from world war ii, korea, and vietnam. All passed over at the time because they were hispanic, jewish or africanamerican. The ceremony is 70 years in the making. As one Family Member has said, this is long overdue. Reporter only three including Melvin Morris are living today. One by one for more than an hour, each citation was read. Knocking out the enemy mortar position and destroying both bunkers and killing their occupants. Reporter the president presented the highest military honor to the families of those who dedicated their lives to their country. As one of the original army green berets, Staff SergeantMelvin Morris volunteered twice for vietnam. A battle in 1969 was almost his last. I went in and threw hand grenades everywhere. Reporter under relentless enemy fire, morris was gravely wounded, shot three times while retrieving the body of his team sergeant. That same year, specialist santiago ettevia was pinned down, the soldier next to him shot dead. Surprisingly, morris doesnt believe he was the target of discrimination on or off the battlefield. It didnt matter, we all bled the same blood. Reporter the things morris cherishes most, his service and his green beret. Its beat up, sewn up and survived. But ill never wash it, because i always said, let the blood, sweat and tears stay in it. Reporter jim miklaszewski, nbc news, the pentagon. And still ahead for us tonight, our nbc news investigation, how General Motors quietly changed the design of defective ignition switches but didnt alert drivers until it was too late. Later, there are good reasons for it, well explain why, something with a funny name always happens to be one of the Fastest Growing physical activities in this country. Were back as promised tonight with our nbc news investigation, the damage control continues for the nations top carmaker. A day after apologizing for General Motors mishandling as massive recall last month and announcing another one. Mary barra said shes creating a flew position of Global Safety director. Much of this centers on how the company quietly changed the design of a flawed ignition switch. The decision that may have been the difference between life and death. Nbcs Gabe Gutierrez has our report from detroit. Our whole lives were changed in the blink of an eye. Reporter the night Brooke Melton died, her dad made a promise. I whispered, brooke, i will vindicate your accident, because i knew it was not her fault. Reporter the 29yearold was driving her 05 cobalt when the black box data shows the ignition abruptly shut down. Mark hood testified for the family in its suit against gm, which ultimately was settled for an undisclosed amount. He says the faulty ignition slipped out of run because of this critical part called a plunger. This is the Spring Loaded plunger that holds the switch in position. Reporter it fits into each slot, holding the ignition switch in run or accessory. The problem is, hood says, this tiny part in recalled vehicle was too short, making it possible for the ignition to shift while driving. The air bags are disabled, the power steering is disabled and the power brakes are disabled. Reporter during the 2007 model year gm replaced the old part with this one, a longer plunger. The difference, 1. 6 millimeters, the width of a quarter. The longer plunger and longer spring is more likely to stay in the run position. Reporter now, federal regulators are formally demanding answers. Who at gm signed off on the change and why they werent notified. Gm had an obligation to notify nhtsa that there was a defect, and they had the obligation to recall the earlier models with the unsafe part. Reporter in video depositions obtained by nbc news, a gm design engineer responsible for the cobalt ignition switch says he doesnt recall ever authorizing such a change. If any such change was made, it was made without your knowledge and authorization . That is correct. Reporter we couldnt reach him for comment, but we did stop by the home of another engineer who later headed up gms internal investigation. Reporter mr. Stoffer reporter but he didnt want to talk to us. Gms new Ceo Mary Barra declined an interview, but released this statement yesterday. Something went wrong with our process in this instance and terrible things happened. Reporter four days before Brooke Meltons accident her father says the dealership in georgia told her there was no fix. That was in 2010, nine years after gm first noticed the problem, and four years after the Company Changed the ignition switch in new vehicles and in replacement parts. But Brooke Melton and her father didnt know. Because gm didnt tell them or anyone else. Right now theres a federal criminal investigation underway, and congressional hearings are being planned for next month. Today gms ceo reiterated the company is cooperating fully with regulators, brian. Gabe gutierrez reporting from detroit with us tonight. Gabe, thanks. Were back in a moment with the sobering news out today of what awaits so Many Americans when work is over. The world of fashion remains stunned by the death apparently by suicide of lauren scott. Found dead in her new york apartment yesterday. The Rolling Stones today announced the postponement of their remaining tour dates in australia and new zealand. Scott and mick jagger had been in a long term relationship. Some grizzly news came out this week, pertaining to working americans, in the form of new polling stats, about what awaits them after a lifetime of work, 37 of American Workers say they are somewhat confident about having a comfortable retirement, while 18 are now very confident. Heres the killer, 36 of American Workers have less than 1,000 in savings and investments. So many are simply trying to live for the present day, buffeted by economic downturn and a changing u. S. Economy. If youve been to disney world, you may remember the trex cafe, and if you know disney employees, youll recognize their legendary calm in the face of adversity, as the aquarium fish tank in the center of the restaurant breaks. The water and fish flood in, the patrons, those who werent stopping to take pictures, were ushered out swiftly. The employees used nets and trash bags to scoop up all the marine life they could. Up next for us tonight, the new racquet in town happens to be one of the Fastest Growing physical activities in america. Finally tonight, if youre like me, the older you get, the better you were as an athlete back in the day. Most folks still feel like they have a lot of fight left in them, even if they cant cover as much ground as quickly as back in the day. That may explain the rise of a sport growing in popularity. If you heard of pickleball or you already play it, then you know. If youve never heard of something called pickleball, youre about to get a crash course in a fast growing activity from nbcs mark potter. Reporter if the pickleball craze has not yet hit your town, stand by, its on its way. Pickleball is one of the Fastest Growing sports in america, and can be played by just about anyone. Including 91yearold lee kritzer, vying for a medal at a pickleball tournament in del ray beach, florida. It gives you exercise. Its fun, social and competitive. Reporter although its exploded recently, pickleball was invented almost 50 years ago near seattle. A combination of tennis, badminton and pingpong. Its played with a paddle and a whiffle ball on a short court. This attracts older players who can still win without having to run too far. You can compete with the younger people by using your head. While they try to use their speed. You out think them. Reporter watching this game being played, you might wonder why its called pickleball. Over the years its been widely reported its been named after the inventors dog, pickle. The inventors wife said the name actually came from a sport of rowing, where a pickle boat has a mixed crew. Just like pickleball is a mix of other sports. The american pickleball capital may well be the villages, a huge Retirement Community near orlando. Even with 140 pickleball courts, players form lines each morning to get a game. Looking good. Reporter these women are passionate, much friendly competitors. Every wednesday we start off with golf in the morning. Then we go to lunch. And then we play pickleball. Thats our triathlon. Reporter the usa Pickleball Association says the game is spreading around the world and easily has more than 150,000 players. A fun, fast moving sport with a funny name. Mark potter, nbc news, orlando. Thats our broadcast on a tuesday night. Thank you for being here with us. Im brian williams, and, of course, we hope to see you right back here tomorrow evening. Good night. I seen a lot of red tape, and i seen policemen all over. Thats whey neighbors say in this neighborhood, a deadly shooting. What they found inside the home that could have police solving multiple crimes. Good evening. Im jessica aguirre. Im raj mathai. Most neighbors had no idea what was happening inside the home. Its san joses ninth homicide of the year on epling lane. Marianne favro has the latest. Reporter raj, a man was shot to death inside this home and a neighbor across the street tells me she heard several shots fired last night. We have also learned that homicide may not be the only crime committed here, sources tell us this was a marijuana grow house. Tonight police are looking for the person who shot and killed the man inside this house on epling lane investigators have not released a name but said he was in his late 20s or early 30s. I was home all day. I didnt hear no gunshots or anything. Reporter she was surprised to learn she may have been living next door to a marijuana grow house. Sources tell us there were pot plants growing in some bedrooms. A pg and e employee was called out to shut off the power after someone apparently manipulated