CNN Anderson Cooper 360 May 13, 2015 03:32:00
Switching systems, and see if there were any anom lis anywhere. and, you know, the fbi always shows up at transportation accidents, with the ntsb. and until it's determined that it's not a crime, they stay on scene as a co-investigator, when it's determined that it's not a crime, they offer all of their assistance so there's been a pretty good working relationship between the ntsb and the fbi for about, for, you know, close to 20 years now. >> we're also hearing there are reports about that a csx freight train may have been involved in this. and csx is denying those reports and saying they hav...