Train Use News Today

Welcome back. youre watching msnbc. it may be months before investigators know exactly what caused the switch error behind this weekends deadly train crash down in south carolina. the head of the ntsb says positive train control technology likely would have prevented this tragedy. two people were tragically killed and more than 100 hurt. nbcs maya rodriguez is in lexington county, south carolina, near the crash site. what is the focus for investigators today? >> the ntsb is going to be looking i...