TODAY | March 10, 2014
>> and search teams scour the ocean for signs of that wreckage, troubling questions do remain. nbc's tom costello has been following the story around the clock since it broke, tom, good morning to you.
>> good morning, matt. investigators in both the u.s. and asia are quite simply baffled. no emergency transmitter signal, to sign of wreckage in this heavily traveled body of water. it now appears that fuel slick may not have been associated with the downed plane at all. the radar tapes show the plane may have made a turn as if it were starting to turn back.
>> in the waters south of vietnam, a massive international armada searching for the remains of flight 370. but so far, only unconfirmed sightings of debris.
>> we have not found anything that appears to be objects from the aircraft.
>> after zeroing in on a fuel sheen spotted over the weekend, the search has expanded and intensified with still no confirmed sign of the plane that disappeared from radar.
>> this is a very large search area.
>> we caught up with commander william marks .
>> you have to take into account wind and current and sea state . and as each hour passes, that area grows bigger. so right now, it is a very large search area i estimate could be easily hundreds of square miles .
>> the loved ones for the 239 people onboard continue to wait. among the passengers, phillip wood, an ibm executive from texas. he was home just last week.
>> had a good meal together. and it was just a good quality time, you know. so i'll always keep that in my heart and memory, you know, as kind of a good-bye dinner.
>> flight 370 was flying at 35,000 feet and roughly 500 miles per hour when the malaysia military says it seemed to turn back before then disappearing from radar. if it suddenly broke up in flight, the debris could be spread over a massive area. but what could've happened. the possibilities include a calamitous malfunction, a structural failure, even a bomb.
>> something occurred that required their immediate attention. and they were unable because of task priorities to need to talk to air traffic .
>> the u.s. government is helping to review the names and surveillance camera images of every passenger who boarded after investigators learned two of the passengers onboard were using stolen passports. they'd each booked one-way flights to beijing. the question, were they criminals, terrorists, or simply trying to get past immigration?
>> the ntsb is also assisting the malaysians in this investigation. there is no evidence of terrorism. but the fact this plane lost contact so abruptly is a cause for concern. u.s. officials say they have seen nothing so far to suggest terrorism.
>> tom costello on this, thanks