CNN Anderson Cooper 360 May 13, 2015 03:04:00
>> reporter: hi don. we're told that the fbi has now responded to the scene to help with -- assist with the investigation. right now, the only indications are there's at least 50 people who have been injured and there's no indication at this point -- again, everything is very early in the process. but the federal response is already there, trying to assist the local authorities and assume at some point the national transportation safety board will be involved and will probably lead in the investigation, at least until, you know, to try to figure out what happened here with this train. but at t...