and that required some -- as you can see in some of the pictures, the traffic situation was horrible. they say the emergency rooms are fully up and running and taking those patients in. let me go back to you, gus, because nbc has learned that these tracks have what is called positive train control. explain for folks who don't know this stuff what is positive train control and what could that tell us about this? >> positive train control was something that the federal government mandated after the 2008 metro link crash in california. basically as far as accidents go, it says that if -- there's a restriction, what we call a civil speed restriction coming to a real sharp curve that requires a train to slow down. if the engineer doesn't do it, if he doesn't slow the train down, there's a system that will automatically slow the train