todd curtis, dr. curtis are you there? >> i can hear you. >> while we are speaking the govenor has arrived on the scene as well as police commissioner ray kelly. so, dollar dr. curtis to be cles very, very early on this very lengthy investigation. as you have been listening this morning the early witness accounts the train was going fast. the trains go fast. do we really know what that means right now? >> we don't. because how fast the train should be going in that particular section of the track will depend on several factors. and one of the factors that was mentioned a few minutes ago was the fact that the train was being not pull by a lyco mow l , it was pushed by a locomotive. it te depends on the procedure f the rail company. >> tell us what is different if it was pushed by a will h a loce rather than pulled. this has been a train that has been up-for-quite up for quites they have specific pro see procs for what kind of locomotion should be done for this kind of situation. given the passenger load and the number of ca

todd curtis our transportation contributor your expertise has been so needed this morning. needed because we have been talking about what you see here. the train derailment of the hudson live the metro north rail. four people lost their lives as a result of what you see here. we are expecting another press done for instancconference somes morning. wwe know the ntsb will be here o start the investigation here. the what and why of the train derailment in bronx, new york. keep it on al jazeera. i'm john seigenthaler, and here's a look at the headlines... >> al jazeera america, there's more to it. >> i'm phil torezz, coming up next on techknow. >> hike! >> america's favorite sport is under fire. >> now, that impact simulated 100 g's of acceleration in your brain. >> it's the opponent no player can see. >> so the system is showing real-time impact. >> can science prevent concussions? >> i did my job and just had to sacrifice my brain to do it. taken to the streets in kiev. they have escalated and they are demanding a new election and the impeachment of the press ar president. th

some of them serious we are joined by todd curtis on the phone our reporter on the scene described these four fa fatalits have not been removed from the scene. is it possible that is because the bodies are city there as part of the ntsb investigation? those investigators that just arrived on the scene and maybe to give them a full assessment of the scene, is that possible? >> it's more than likely. typically the ntsb does not have that expertise. they rely on the authorities at the scene to provide support for things like dealing with the injured and with the deceased. although the positions of the bodies et cetera would be important for the investigation of the ntsb, it's a very unlikely in my opinion that they are being held there for the ntsb. it will be up to the local authorities, the medical examiner or the equivalent to make a decision as to when those bodies will be removed. >> our understanding is that the ntsb has just arrived on the scene and in fact, just held a news conference and we'll be getting you the information on that. are we going to play that now guys? todd, stay cl

. >> our transportation contributor todd curtis joins us were boston. what did we learn from the hearings? >> we learnt a variety of detailed information about the crash. the general aspects of what happened has been fairly well-known for several months. what we had here today was basically in open testimony. the designers of the aircraft talking in detail about what the expectations were for pilots that they train. that may be a key here. the boeing representatives expected any airline trained to fly the aircraft. an aircraft pilot to have certain skills, and it seems as though in this case those skills may not have been there or been strong enough to deal with a situation like what happened in san francisco. >> is the problem with tripping? >> it may be training and aircraft procedures, and assumptions made by the designers of the aircraft. it go back to the design on the 777. were there assumptions made by pilots, going into the future? as the faa reports perhaps some of those that the airline pilot would have basic skills, perhaps they are no longer

we'll talk with aljazeera's transportation contributor ted curtis and breakdown -- todd curtis ratherout what happened here. >> a lot of important questions raised in that investigation. thomas, saturday marks the one year anniversary of the newtown shooting in connecticut. the violence sparked a debate not only about gun control, about how to treat mental health in this country and its role in these kind of acts. we're going to take a look at where we stand in these issues one year later. >> ntsb investigators held a hearing in washington on wednesday to help determine what caused the crash of asiana airline flight last summer. newly released video of the crash shows just how vital the accident was as the plane broke apart after hitting a sea wall while attending a landing. investigators highlighted a number of problems, including confusion about the automated control system and pilot concern about landing the plane without visual assistance. >> we do have an issue that needs to be dealt with with respect to automation and performance when it comes t to e interaction between the airc

todd, thank you for joining us this morning, mr. curtisrth is the fourth busiest commuter rail line. 26,000 passengers ride it each day. turning to weather, some parts of the country are getting hit with cold temperatures they haven't seen in years. >> i wish i had better news on a monday, but we are going to have a potent arctic system moving across the country and really dropping temperatures. we're getting specific moisture with this, too. we will see the rain, which we've already had in places like washington and idaho, but then also the cold air from canada will drop temperatures in a lot of cases 30 or 40 degrees from what we're seeing this morning but the time we get a couple mornings from now. here's where we have the storm system now. the cold air hasn't quite moved in. the temperatures this morning are deceiving, because you're walking on you the door saying this us mild out here. this isn't a big deal. it is coming. that will switch some areas into snow, but we'll get a chance for freezing moisture on the roads. we have a wind c