Detailed text transcripts for TV channel - CNN - 20171220:09:46:00
Traffic control which is ctc, and this is a system that allows for dispatch direction over the train. ctc is not ptc, however. ctc cannot enforce speed restrictions on a train like ptc can. >> two of three people killed in the derailment have now been identified. jim hamre, zack willhoite were members of the rail passengers association. still no explanation for why the train was going 80 in a 30-mile-per-hour zone. the ntsb is waiting to interview crew members who are hospitalized. >> reporter: we're learning new information from the ntsb about the moments before this devastating train derailm...