occurred -- >> what does that mean? >> well it's called access on amtrak and what it is it reads the speed of the train and it compares it to what the mandatory speed is and it will stop the train in the fact that the engineer is speeding. it was not on this track at this time. >> jim 71 years ago, some people have been comparing it to one of the worst train accidents in our nation's history, 1943 killed 79 people and injured 117. it just so happens that the crash last night was almost an exact place of this crash in 1943. it sounds like the track has not been updated much. has there been a concern that something like this might have happened? >> that's up to the ntsb to answer. one of the most wanted recommendation is positive train control and positive train control had it been in effect in this area -- it's now man damted