happening now, our special coverage of the mystery of flight 370. air crews are about to return to the search area where another possible signal from the jet's black boxes was detected. are they getting closer to finding a crash site? we're learn new details, including maneuvers that may have been intended to dodge military radar. plus new confirmation the final message from the cockpit to the tower was spoken by the captain. we'll break down all the new information and what it means for the investigation. we want to welcome our viewers in the united states and around the world. i'm wolf blitzer. you're in the "situation room." >> this is cnn breaking news. we're following several breaking developments in the flight 370 mystery. right now, experts are analyzing what could be the fifth signal from the missing jet's black boxes. planes are about to take off for the area in the indian ocean

where the electronic pulses have been heard. the search zone is the smallest it's ever been as the crews race around the clock hoping to hear more pings and find actual wreckage. our team of experts standing by in the "situation room" to help us understand what it means and kcorrespondents have new information about the search and the investigation. let's go first to our aviation correspondent, rene marsh for the very latest. rene? >> wolf, another day, another potential ping in the same area as the others, but this time it was detected with a totally different piece of equipment the search for flight 370's black boxes intensifies and the ping count may have gone up again. an australian orion aircraft flying over ocean shield dropping uoys in the water below and at least one got a hit. a possible fifth ping detected where ocean shield already picked up four. that could be a confidence

builder. >> the fact that it's picked up by a sonabuoy which is probably less well equipped to detect that signal than the pinger locator, that would indicate that, perhaps, it is still a pretty strong signal. >> reporter: the acoustic data is being analyzed, but the search coordinator says it's potentially from a manmade source. like a flight data recorder. an underwater listening device is attached to the buoy. an antenna relays what it's hearing to the aircraft. the sensors are deployed at least 1,000 feet under water but only work for eight hours. sonabuoys usually used to detect submarines were not designed for this kind of mission. >> the ones i'm familiar with generally have very poor response to frequencies as high as 37 kilohertz. they're more used for detecting mechanical sounds of submarines, 1 kilohertz or lower. but that's not to say that there

haven't been some changes made. >> reporter: the search area surrounding the ocean shield continues to intensify. the british ship, hms echo, has pulled out of its position to the southwest and is now focusing where the pings have been detected. but crews continue to listen for even more pings to shrink the search zone. a smaller zone is necessary. the underwater vehicle can only search 40 square miles a day. that means the roughly 500-square-mile area where the pings were detected over a span of three days would take nearly two weeks for bluefin to search. and today, u.s. navy supply ship joined the mission for the search of flight 370. the ship could be used to replenish ocean shield and others participating in the search. essentially, it can supply them with food, water, and fuel, an indication this mission isn't ending any time soon. wolf? >> that's correct. stand by, rene.

i want go to perth, australia, the base of the operation of the search. michael holmes is on the scene with more. what's the latest there, michael? >> reporter: yeah, we're going to have the search planes out again. more than a dozen of them, wolf. they'll be leaving in the sectithefection few hours. also, those ships, again, are going to be scouring the ocean today. something rene mentioned is really interesting. ocean shield joined now, we reported this to you yesterday, that it was headed to the ocean shield area. the search area where they've been getting these pings. now, hms echo, it's a british naval ship. now, what it is, it has the ability, it's an oceanography ship. it has the ability to scour the ocean using echo sonar. scouring the floor obviously trying to find evidence of wreckage below. now, as rene said, this bluefin submersible, it's a tedious operation with that. it goes literally at walking pace, takes a full day to go down, cover some space, come back up.

the hms echo, though, it's got a two-mile-wide coverage. it's not high resolution like the bluefin submersible, but way broader brush strokes, if you like, and much faster. we've talked before about the silted bottom down there. perhaps meters of silt at the bottom. that would give off this echo from hms echo would give a soft signal back, if you like. now, that means that if there is a plane down there or wreckage down there, it would give off a hard signal. so it's obviously out there to sort of help now that we know those pings are in that area. going to go do broad brush strokes and see if they can found wreckage. meanwhile, the other ships are a few hundred miles from the west where experts think any debris from the suspected crash site would have drifted over the weeks since mh-370 disappeared, wolf. >> michael holmes on the scene for us in perth. thank you. we also have new compelling details of what may have happened in the first few hours

after flight 370 went off course. senior correspondent joe johns is joining us from kuala lumpur, the malaysian capital with details. joe? >> reporter: wolf, the new details suggest a familiar scenario in crisis management, that in the early hours when flight 370 disappeared, the malaysian military could have been acting on information that civilian authorities didn't get access to until later. though the government is already denying it. it has been one of the lingering mysteries of flight 370. what happened in those first few hours after it went off course. now we're learning the plane disappeared from military radar for 120 nautical miles after it made that left turn and crossed over the malay peninsula. and new details about what happened in those predawn hours. a senior malaysian government official and a source involved in the investigation tells cnn the plane must have dipped in altitude to between 4,000 and

5,000 feet. a possible sign the pilots were at the controls. but it's still unclear if the plane was in some sort of trouble. whether they were purposely evading detection, or whether the malaysian radar system failed somehow. >> it's not telling us very much other than they may have been switching pilot responsibilities at the time. so whatever event happened, whatever was planned, whether it was nefarious or mechanical, it happened as a result of that transponder and that acars getting shut off. >> reporter: what is clear now, mh-370's captain ahmad shah, not his co-pilot, was the last person on the jet to speak to air traffic controllers telling them, "good night malaysian 370." malaysian sources tell cnn. the sources said there was nothing unusual about his voice which portrayed no indication he was under stress and no third voice is heard. and just today, more than a month after the flight

disappeared, we're learning malaysian air force search aircraft were dispatched soon after the airline reported its plane missing. malaysian sources told cnn. headed for the strait of malacca and south china sea. authorities had initially focused their search on the china sea. it took off before authorities corroborated data indicating the plane turned suddenly westward from its original course. the malaysian government denied in a tweet that any malaysian air force aircraft were scrambled. >> i'm suspicious of the information that they've provided. i think the most likely scenario is that they detected them on military radar, they scrambled those jets and either couldn't locate it or some other problem. >> reporter: our source says the air force did not inform the rest of the malaysian government until three days later, march 11th. a source involved in the investigation told cnn malaysian

police continue their criminal investigation into the disappearance of the plane and say no conclusions have been reached. the home minister here reiterated at a news conference on thursday that 180 people have been interviewed including family members of the cabin rue. wolf? >> joe johns with the latest on the investigation in kuala lumpur. let's bring in our panel. rene marsh is back, along with our aviation analyst miles o'brien and peter goelz and tom fuentes. what do you make of this notion the plane suddenly went down to 4,000 or 5,000 feet and may have been trying to avoid military radar detection? >> there's lots of things wrong with it, wolf. it just doesn't add up. the ability to get down to that altitude and back up to another altitude, although i question all the numbers we have gotten are in question. the fact that it might have been down at 4,000 or 5,000 feet as it potentially crossed the

malaysian pensiinsula which has peaks of 7,000 feet confused me as well. is this an above-ground a altitude or above sea level altitude? there's a lot of questions here. with all of that, 4,000 to 5,000 feet is not an altitude where most pilots would expect not it be painted by radar. it doesn't add up. i'm not sure what they're try to say with this. >> if it's true, tom, what does it say to you if a plane is normally supposed to be cruising at 35,000 feet and suddenly goes down to 5,000, what does that say to you? >> says it changed altitude, wolf. we don't know why. we don't know who was at the controls. if it's true. i'm not buying that yet. i think the reporting on their radar sightings from the beginning of this investigation have changed. different stories have come out about changes in altitude, direction, speed. and then multiple changes of direction. so i just -- you know, again, i'd like to see proof, and right

now what they're offering is sthi since they don't know for sure what it did, they're assuming when it went off radar, it must have gone down below the radar. that's not how you arrive at conclusions in an investigation because of a negative, you say that the opposite must have happened. >> if it did go down to 4,000, 5,000, peter, what does it say to you? >> well, it says somebody was in control of the plane, but i'm with my two colleagues. the malaysians have not been forthcoming throughout this investigation. and even in today's report, did they scramble two jets? or didn't they scramble two jets? and why are they revealing this 35 days after the accident? this is stuff that should have been clarified within 24 hours after the accident. the radar data should have been looked at within 72 hours. and people should have had a clearer picture. and this has been a mess from day one. >> i want all of you guys to

stand by for a moment. i want to bring in another aviation analyst, geoffrey thomas who's joining us from perth, australia, right now. he's the editor in chief of airlineratings.com. what are you hearing over there in perth? you're there where the staging area is. what's the latest on this entire investigation? specifically the notion that the plane at one point may have gone down to 4,000 or 5,000 feet in altitude? >> yes, wolf. those detail about the change in altitude, we've known about that here for about three weeks. this was -- this came out of malaysia -- some of the malaysian military failure early on. again, off the record. now we're getting something more on the record. and as your panelists have just suggested, the variations in what we're getting out of malaysia has not been good. it has been inconsistent. it has been contradictory. and that's led to a lot of

confusion in the reporting and more to the point, a lot of confusion in the analysis of exactly what's happened with this airplane. my sources tell me that there were multiple changes in flight path, direction, and there were a number of changes in altitude. the specifics, we don't have as yet, but clearly this airplane was under the control of somebody. and we're yet to find out exactly who. >> we've now confirmed, malaysian authorities apparently have timely concluded that the voice, the last voice heard from the cockpit was the voice of the captain. not the co-pilot, if you will. what do you make of that? >> well, you're right. they have said that, but was the co-pilot doing all the air traffic control communication up to that point and then the captain signs off?

because if the captain signed off, that would indicate that the co-pilot was no longer in the cockpit, back doing something which would kind of support the captain was the man in control for the rest of the flight theory. so that detail, i haven't got as yet. i don't believe it's out as yet of exactly what was making all the air traffic control communication up to that point. >> let me bring rene into this for a moment. rene, what are you hearing from your sources about this notion that the pilot actually was the last one who said, "good night malaysian 370"? >> well, wolf, you know, i guess the big question in all of this is, if this is true, if it truly was the captain who said those final words, what does it all mean? and in the grand scheme of things, we may be able to assume a couple of things. we may be able to assume that if the captain was one who was speaking to air traffic control, perhaps the co-pilot was the one

who was in control of the plane. although that isn't necessarily true. it could be that, perhaps, under certain circumstances, the captain needed to be speaking to air traffic control and still be in control of the airplane. so i guess what i'm getting at is that now that we have this detail, it really doesn't change a whole lot. it really doesn't tell us a whole lot. and it really doesn't move us that much further. wolf? >> you know, miles, i think a lot of us would be happy if they released a transcript, malaysian authorities, if they released a transcript. why not release the audiotape so we could all hear those words? >> why not? very good question, wolf. that's a reasonable thing to expect at this time. i can't imagine how at this juncture it would in any way impede their ability to conduct the investigation and it would just be a breath of fresh air for an investigation which has not had anything but secrecy surrounding it.

i understand when you're conducting the criminal side of an investigation, you need to keep things privileged, but there's a lot of aspects to this investigation that could be shared with the world, and frankly more ears hearing things, the better. just one final thought here. it could have been as simple as the first officer was conducting a public address announcement as they leveled off, and the captain handled that particular radio call. i don't want to put too much into that particular thing. >> yeah. let me bring geoffrey back into this. this fifth ping that they suspect actually came from one of those two black boxes, i know it hasn't been confirmed yet. certainly not as strong as the first four that had been detected. geoffrey, what are you hearing there in perth, australia, about this fifth suspected ping? >> yeah, well, the p-3 orions are dropping these sonabuoys. the ping won't be as strong because it's a different sort of mechanism to listen for the

ping. what it does, the sonabuoy drops on the surface, deploys a 1,000-foot cable and on the bottom of the cable is a hydrophone. it's listening from 1,000 feet deep, whereas the towed pinger is right down at the bottom. so it's getting a much, much stronger signal. so the weakness of the signal would be indicative of the fact that its hydrophone is much higher up in the ocean. so this just adds to the number of pings we've had. it seems to corroborate the fact that we're right on where the resting place is of 370. >> peter, it's, what, 35 days. those batteries are supposed to last a minimum of 30 but sometimes they go longer. we're right now certainly at the tail end of the battery life of those two black boxes. right? >> there's no question. the clock's ticking. but, you know, we've had some good luck during the last week. let's hope we continue to have it. we need to pick up probably

four, half a dozen more pings to start to narrow that search area down from the 500 square miles that rene reported it currently is. >> and, rene, you're there for us still. what are you hearing from your sources right now? do they anticipate that, you know, the next few hours they're going to be able to announce maybe there have been some more pings? >> you know, at this point, we don't know if there have been any more pings. we do know that hms echo now in the vicinity, wolf. we know that it has the capability of listening as well. it has passive sonar. also has the ability to map the ocean floor. although they haven't given us much detail as far as what the specific task of hms echo will be in the area. we know that the ocean shield is leading the charge as far as using the pinger locator to pick up more pings. but we'll just have to wait. we're hoping to get more information as these press conferences happen.

midnight for us here. but whether they detected anything else from the time that they last announced it, we don't know. it's quite possible. now you have the pinger locator. you have the sonabuoys in area and also have hms echo. so lots of assets. f they are listening for those pings. will we get good news later on today? i'm going to bet the search crews are hoping so, wolf. >> are you surprised, miles, 35 days in they're still hearing pings? >> you know, aviation is the kind of thing where there's always margin that is added. whatever you build, if the spec is 30 days, the engineers are really building it for 40. that's just how aviation is as safe as it is, and that's just how engineers who are involved in this business operate. so it doesn't surprise me too much. you know, what i was concerned about was that they operated in the first place. were they damaged on impact? if the pingers were to start going, the fact that they're

going past 30 days shouldn't come as too much of a surprise to us. >> all right, guys. stand by. we have a lot more to assess. still ahead, the dangers in the deep. why the underwater search for flight 370 is to slow, so risky at the same type. we'll also talk about the enormous challenges of recovering wreckage if and when it's found. it could take years. maybe even decades. there's a saying around here, you stand behind what you say. around here you don't make excuses. you make commitments. and when you can't live up to them, you own up, and make it right. some people think the kind of accountability that thrives on so many streets in this country has gone missing in the places where it's needed most. but i know you'll still find it when you know where to look. frequent heartburn? the choice is yours. chalky.

not chalky. temporary. 24 hour. lots of tablets. one pill. you decide. prevacid. ♪ 24 hour peoi go to angie's listt for all kinds of reasons.

to gauge whether or not the projects will be done in a timely fashion and within budget. angie's list members can tell you which provider is the best in town. you'll find reviews on everything from home repair to healthcare. now that we're expecting, i like the fact i can go onto angie's list and look for pediatricians. the service providers that i've found on angie's list actually have blown me away. find out why more than two million members count on angie's list. angie's list -- reviews you can trust.

"crossfire" won't be seen tonight so we can bring you more of our special coverage of the flight 370 mystery. we're following the breaking news. a possible fifth signal from malaysia's flight 370's black

boxes. the air search is resuming now in the smallest area yet with ships crisscrossing the area around the clock. cnn's tom foreman is digging deeper into the huge challenges searchers are still facing. what are you finding out, tom? >> wolf, when you go under water, that's when it really gets complicated. here's one way of looking at it. more people have been to space than have been in the deepest parts of the ocean. and this area with the target zone anywhere from 1 1/2 to 3 1/2 miles down. that absolutely qualifies as deep ocean out there. comparison, we're talking about an area that is much deeper than where the titanic is, much deeper than where nuclear subs normally spent their time. deeper than giant squids live. is absolutely close to freezing down there. not quite frozen but almost icy temperatures down here. complete darkness. they don't know much about the ocean floor here, wolf. they know it's a general slope but don't know exactly how steep it is, exactly what features are down there and what could interfere with the underwater search as they move that

direction, wolf. >> why not send those robotic mapping devices down immediately to start looking around? >> precisely because they don't have all those other answers. when you bring in these features like the bluefin, for example, to start mapping down here, it helps if you have an idea where you're sending it because the closer it can be to the ocean floor, it's using side scan sonar, the better an image you can get. you don't want it right on the ocean floor. you're also functioning here kind of at the limits depending where you are. it's designed for 2 1/2 miles down, 25 hours at a time. using sonar acoustics to take images of the ocean floor. these are typically used at much more shall dow depths. to a degree, any time you put it this deep in the water, there's an experimental edge. you're trying something you haven't tried before. if you want higher quality images like some of the other types of sonar that work closer down here, then you need to know even more because then you're talking about being maybe 3 or 5

yards off the ocean floor and with an expensive and highly sensitive piece of equipment like this, you don't want it colliding with things, getting stuff and losing valuable time. that's whey thooy they're waiti that and focusing on the work on the surface. the ships like the hms echo. what it can do is give them a better picture before they start, wolf, of what they're taking pictures of so hopefully when they put the bluefin down there, it can be the most productive. because the big production to get it into the water and get it out safely, they don't want to lose any of that time through bad planning. >> very, very, very complicated. tom, thank you. colleen keller, senior analyst with the scientific consulting firm metron. worked on the search for air france flight 447. and eric is joining us from sydney, he's an oceanographer with the climate change research center. talk a little bit about these waters. how challenging, eric, are they

for searchers? >> well, they aren't very challenging, and it's just so deep. once you get down to the ocean floor, really we oceanographers, we've only done this for a little amount at a time and we haven't just had time to map everything. and most of our focus has been on the other oceans, not on the ocean here, the indian ocean off australia. >> colleen, you worked on the reofry, the black box from the air france disaster off the coast of brazil in the atlantic ocean. looking for a small box like that, a flight data recorder, a cockpit voice recorder, even if you have a general area, how difficult would it be in the indian ocean right now? >> well, you know, the depth compounds the problem. it just takes an awfully long time to drop the vehicle down there and then the sensors that you're using aren't like just using your eyesight. you do use camera, but it's dark. the side scan sonar, the images aren't like a photograph.

they cast shadows. the sound waves cast shadows on things that the waves bounce off of. so you need somebody to kind of interme interpret the pictures that result from the side scan sonar to see if they identify anything manmade. then there's the whole fact they don't really know what's down there so, you know, like what was being said, you have to worry about tangling the bluefin-21 into something, some wreckage or some kind of features on the bottom, and if you lose that, then you've lost a whole month to get another submersible out there. >> one of the great submysteries of all of this, eric, if you believe those four pings were from the two black boxes or at least one of them and now maybe a fifth ping come from one of those black boxes, yet no debris has been found at all on the surface or any place else. what's your assumption? what's going on here since you know these waters well? >> yeah, so i -- one way that's going to explain this is really

the debris has gone into a very different direction. much of the focus, especially early on in this search, has been about the debris moving eastward. moving toward the strait. now that these pings seem to be much further northward, much closer to malaysia and the plane maybe hasn't flown that far, it means the circulation actually would have driven the debris the other way around, much more toward madagascar, toward africa, even. >> colleen, here's a mystery that i'd like you to explain to our viewers. the pinging sound that's coming from those two black boxes, they're supposed to be, what, 37.5 kilohertz, but we're told it was slightly different the first four pings that were detected, this fifth suspected ping. not exactly 37.5. how -- if they believe they're coming from the black boxes, what would explain the slight change in the kilohertz? >> well, it could be the environment or it could be the

box, itself. i know that when they recover one of the black boxes from the air france search and put it on the bench and cleaned it up and put a new battery in it and tested it, it didn't function at the frequency they were expecting. and it also didn't give the correct voltage that they were expecting which indicated that either the box had suffered some sort of damage -- i'm sorry, the beacon had suffered damage or that it was manufactured incorrectly or had some defect inside. so it could be any number of explanations. including maybe that the water environment is changing the signal, but i think it's probably more likely it's coming from the box at that frequency. but the manufacturers still seem to think that it's coming from their beacon. so we're going to go with that. >> we heard in the last hour, colleen, from one of the new zealand air commanders there who's been involved the surface search is now about the size of west virginia. looking for debris that may be floating on the surface. but the search underwater based on those four or five pings is a

lot, lot smaller. how much smaller is it based on the fact that those pings were found about, what, 17 miles apart? >> well, you know, we're giving the towed pinger locator a 1 to 2 mile detection range and actually it might be a little bit manufacture because of the altered frequency that we're hearing. the water actually absorbs that energy less, so the sound can travel farther. so maybe the tpls can see quite a bit differently farther than we expected. but at any rate, let's say you gave it maybe twice the detection range so they could see 5 miles, then the pings we have detected are 17 miles apart and and add another 10 miles, we're talking a 20 to 30 mile square area. that's significantly smaller for the air search area for the floating debris. >> having said that, eric, if you take a look at 20 or 30 or 50 square miles, 3 miles deep, finding those two small boxes, that would be pretty difficult.

you know those waters. >> yes. absolutely. a lot of time on the surface, because we can go down there with the submersible, they don't go very fast. you can't go -- you can drive your ship at the same speed as you an drive your submersible or the other way around. so the submersible can only cover very small amount of distance every day, and every time it has to get back up. this is going to take even for a relatively small area, this is going to take a significant amount of time. weeks, months. something like that. >> you were involved in that air france search, colleen. is there anything you think they need right now? all of the people involved in this search that they're not getting? >> well, you know, it's kind of strange that we're continuing to search the surface for debris. if we found a piece of debris tomorrow, what would that do for this search? i know that when we found debris for air france and we back tr k

backtracked it using three different sets of models, bra l brazilian models, french models, u.s. coast guard models, they all placed the impact point at a different location, and guess what it, it wasn't where we found the wreckage. what i'm trying to say if you don't have very good current models, that debris isn't really going to help you find where you should be looking. so right now i think we should be focusing on the pingers and we should be localizing while we still can hear them then we should just go down right there and start looking with our submersibles. >> colleen keller, eric, we'll check in with both of you tomorrow. thanks very much. still ahead, more breaking news coverage of flight 370. the smallest search area yet. our richard quest is here. he's standing by with the latest. plus, new details of the stabbing rampage in a pennsylvania high school. we're learning more about the teenager accused of the bloody attack. >> why did you do it? ♪

[ female announcer ] f provokes lust. ♪ it elicits pride... incites envy... ♪ ...and unleashes wrath. ♪ temptation comes in many heart-pounding forms. but only one letter. "f". the performance marque from lexus. i'm on expert on softball. and tea parties.

i'll have more awkward conversations than i'm equipped for, because i'm raising two girls on my own. i'll worry about the economy more than a few times before they're grown. but it's for them, so i've found a way. who matters most to you says the most about you. at massmutual we're owned by our policyowners, and they matter most to us. ready to plan for your future? we'll help you get there. co: until you're sure you do.you need a hotel room bartender: thanks, captain obvious. co: which is why i put the hotels.com mobile app on my mobile phone. anyone need a coupon? i don't. afghanistan, in 2009. orbiting the moon in 1971. [ male announcer ] once it's earned, usaa auto insurance is often handed down from generation to generation. because it offers a superior level of protection. and because usaa's commitment to serve current and former military members and their families

is without equal. begin your legacy. get an auto insurance quote. usaa. we know what it means to serve. bulldog: [yawn]

bulldog: i just had a dream i was at mattress discounters with tempur-pedic and the largest selection

of memory foam mattresses under one roof! icomfort, by serta... optimum, by posturepedic... ahh! comforpedic, by beautyrest... ooh! 48 months interest-free financing, free delivery, and queen-size memory foam mattress sets as low as $697! that's more mattresses than you can shake a bone at. ♪ mattress discounters this is cnn breaking news. >> getting some breaking news about a major resignation in the obama administration. let's go to our beya yabrianna standing by with details. >>by just learned from a white house official health and human services secretary kathleen sebelius is resigning as secretary. that she will be leaving the

obama administration. as you know, she's been very much embattled over the last several months ever since the rollout of obamacare. specifically marred by the very poor rollout of the website, healthcare.gov in october. well, as you do know, that website came to its six-month enrollment process at the end of march. there have been some questions over the last several months about sort of what personnel changes might be made. many republicans had called for kathleen sebelius to resign and we now understand that she is, indeed, resigning. according to a white house official. we're also told, wolf, by that official she's going to be replaced by sylvia burwell, omb chief, head of the office of management and budget. that coming to us just now from the white house that embattled health and human services secretary kathleen sebelius, indeed, leaving the obama administration. >> but she's leaving in a relatively high note for as far as the healthcare.gov is

concerned. not just 7 million, today they've announced it's gone up to 7.5 million. 7.5 million people have actually signed up for obamacare. the affordable care act. so that's a pretty positive note, right? >> that's right. that's right. that's a very important point you make. a white house official, we're learning today that even just since that 7.1 million benchmark which was really good news for the white house, saying that 7.1 million people had signed up through that six-month process which really was the goal, wolf, when they were looking at sort of congressional estimates, we had heard that just recently here there were 400,000 more signups. so that was a feeling that even since president obama had addressed that 7.1 million mark, that things had really, i guess, the profile of the program had even been raised. there had been more interest and certainly that was something that the white house looked on as very positively. and we're also understanding

that -- i should clarify, burwell is going to be nominated. loi obviously this is a position that will have to be confirmed by the senate. that's going to be president obama's pick to sebelius sebelius. >> there are still a few days left until the 15th of the month. the folks who couldn't get on tried to get on, they still have a few more days. the 7.5 million number presumably over the next few days, brianna, is going to go up. >> yeah, that's the expectation. there's always this issue, wolf, people who have dined up versus people who have completed the process, who have paid their premium and are completely enrolled at this point. but, yeah, no, this is certainly a good marker for the obama administration. but this has been a very difficult, i would say, six months or so for kathleen sebelius. both in trying to gear up for the rollout of obamacare, and just dealing with what has been politically a nightmare for the obama administration even though recently the tide has turned.

of course, this is going to be, you know, this is going to be an issue that is very much political fodder in this election year. >> former governor of kansas, secretary of health and human services, kathleen sebelius. kathleen sebelius now stepping down. we're going to continue to follow this story. we'll take a quick break. much more on the mystery surrounding malaysian airliner flight 370. richard quest is standing by. we'll be right back. why relocating manufacturingpany to upstate new york?

i tell people it's for the climate. the conditions in new york state are great for business. new york is ranked #2 in the nation for new private sector job creation. and now it's even better because they've introduced startup new york - dozens of tax-free zones where businesses pay no taxes for ten years. you'll get a warm welcome in the new new york. see if your business qualifies at startupny.com to help protect your eye health as you age...

would you take it? well, there is. [ male announcer ] it's called ocuvite. a vitamin totally dedicated to your eyes, from the eye care experts at bausch + lomb. as you age, eyes can lose vital nutrients. ocuvite helps replenish key eye nutrients. ocuvite has a unique formula not found in your multivitamin to help protect your eye health. now that's a pill worth taking. [ male announcer ] ocuvite. help protect your eye health.

the breaking news this hour, we're waiting to hear the results of a new analysis of another signal that may be come from flight 370's black boxes. it's the fifth possible ping detected by searchers since saturday. let's bring in cnn's richard quest. what do you make of this? maybe five pings. that would be dramatic. >> it would, indeed. the way this ping was acquired

is very different. it wasn't done by the towed locator, the ping locator behind ocean shield. this was dropped by an aircraft. it's one of the sonabuoys that's been put into the water and has managed to give a signal. now, what we know is the frequency's in the right area. they don't believe it's of natural origin. and they believe it is a mechanical. but they haven't given us any details. for example, we don't know what the frequency is, we don't know what the repetition rate is. we don't know anything like that. we do know it was at about 1,000 meters. >> 1,000 meters under the surface. we also know now for sure, malaysian authorities have confirmed this that the final words from the cockpit came from the captain, not the co-captain. >> well, it's still -- it's still -- yes, it's believed to be. i'm putting it like that. >> because people who know both voices have said that this is the captain's voice. >> right. >> "good night malaysian 370." the final words from the cockpit. two minutes before the plane made that left turn. >> that's according to a source,

yes, that says five people have heard it, five people have confirmed it's the captain. the circumstances under which that was said, of course, remain completely unknown. and one crucial point, who was the pilot flying? was it the first officer? or was it the captain? because whoever wasn't the pilot flying does the radios. >> why is it significant, though, who said the final good night? >> it's not significant in one sense, yet it's totally significant because we know after that malaysian airline 370 1:19, whatever happened happened after that. so whoever was at the helm of the aircraft was either trying to save it or was involved or somehow knows best what took place. >> what is a lot more significant potentially is if, in fact, the plane went from its normal cruising altitude of some 35,000 feet down to 4,000 or 5,000 feet as it was supposedly

tried to avoid malaysian radar. then it drops down to 4,000 and perhaps too early comes back again, so it is picked up on radar. that is the 4,000-foot theory. there are those who choose to believe it and those who says it doesn't hold much weight. we don't know. >> what do you think? >> i am still skeptical. i think there were altitude changes. i think there is no question there were altitude changes. but the levels involved and the severity, because let me put it another way. why go down when you've already been painted over malaysia? >> does it give us a clue whether it was a mechanical disaster on that plane or it was a criminal act by someone? >> the conspiracyists will say it can only mean one thing. i'm sticking right in the middle. >> richard quest, good work as usual. thank you. we're also just hearing now of

an incident involving hillary clinton. a woman threw a shoe at the former secretary of state during a speech in las vegas. our senior political correspondent brianna keeler is back. working this story. >> we have some video. before we show it to you real quick, we do believe this object was a shoe. to tell you what this event was, it was a paid speech she was giving before the institute of scrap recycling. when this happened, the shoe missed clinton and she actually joked about it. take a listen. >> recycling about -- what was that, a bat? was that a bat? is that somebody throwing something at me? is that part of cirque du soleil? my goodness.

i didn't know solid waste management was so controversial. >> so you have to say there, wolf, she handled this pretty well. and we don't know why this happened. a little bit about what we are learning, according to the las vegas review journal, the woman there you see walking away with the blond hair, she said that it was a shoe. we don't know who she is. we understand from a spokesman for the group before which clinton was speaking that it's not clear what she was protesting, though she was referred to as a protester. she wasn't credentialed for the event, we're told, that she must have slipped under a rope, which certainly raised some security concerns. you can see she was whisked away there pretty quickly. we're not entirely sure who that is. but obviously secretary clinton has secret service detail because she was first lady before as well. but, again, she ducks there as the shoe is thrown at her.

sort of a narrow miss. but i'll tell you, wolf, i've been to a number of hillary clinton events recently. and this here, this is a pretty supportive crowd. this is a paid speech. there really hasn't been any blips really in these events. so this is something that is really, you know, really pretty unusual. >> that could be terrifying. >> sure. >> that's nothing to laugh about. that could be very, very frightening. that shoe, if it was a shoe, could have hit her in the face, causing serious, serious problems. all right, brianna, thanks very much. just ahead, new information coming into "the situation room" on flight 370. we're going to bring you the breaking developments on the search and the investigation, right after this. i'm j-a-n-e and i have copd.

i'm d-a-v-e and i have copd. i'm k-a-t-e and i have copd, but i don't want my breathing problems to get in the way my volunteering. that's why i asked my doctor about b-r-e-o. once-daily breo ellipta helps increase airflow from the lungs for a full 24 hours. and breo helps reduce symptom flare-ups that last several days and require oral steroids, antibiotics, or hospital stay. breo is not for asthma. breo contains a type of medicine that increases risk of death in people with asthma. it is not known if this risk is increased in copd. breo won't replace rescue inhalers for sudden copd symptoms and should not be used more than once a day. breo may increase your risk of pneumonia, thrush, osteoporosis, and some eye problems. tell your doctor if you have a heart condition or high blood pressure before taking breo. ask your doctor about b-r-e-o for copd. first prescription free at mybreo.com

female announcer: it's sleep train's interest free for 3 event.

get three years interest-free financing on beautyrest black, stearns & foster, serta icomfort; even tempur-pedic. plus, get free delivery, and sleep train's 100-day low price guarantee. you'll never find an interest rate lower than sleep train's interest free for 3 event, on now. ♪ sleep train ♪ ♪ your ticket to a better night's sleep ♪

we're following all the breaking developments in the flight 370 mystery. we're waiting for results right now of a new analysis on the latest possible signal detected in the indian ocean. it could be a fifth ping from the plane's black boxes. the air search is resuming in the area where those electronic pulses have been heard. crews are hoping to pick up even more signals, knowing the batteries on the black boxes may die at any moment if they're not dead already. malaysian sources tell cnn investigators now have confirmed it was the plane's captain who spoke the final words from the cockpit to the tower. those words, "good night, malaysian 370." you can follow me on twitter. be sure to join us again tomorrow in "the situation room." watch us live or you can always dvr the show so you won't miss a

minute. that's it for me. thanks very much for watching. i'm wolf blitzer in "the situation room." "erin burnett outfront" begins in 60 seconds.

next breaking news. cnn just learning health and human services secretary kathleen sebelius gone. we are live at the white house. and breaking news on malaysia airlines flight 370. we are standing by at this hour for confirmation of a new ping. officials say this could be from the black box. it's being analyzed at this instant. plus, we now know the last words from the cockpit came from the captain. let's go "outfront." good evening, everyone. we are following two major breaking news stories tonight. the hunt for malaysia airlines flight 370, and the news just