Nightly News | December 04, 2013
>> reporter: the commuter train derailment has thrust the topic of worker fatigue into the news. the investigation, as you may know, is focused on the engineer and whether he fell asleep two weeks into a new shift and a 5:00 a.m . start. everyone gets tired. every shift has its own rhythms. we asked more of those who drive and fly us around, especially in public trance fsportation.
>> reporter: in the first minutes of sunday oos emergency response engineer william rockefeller said he zoned out just before the crash. his attorneys said he was in a daze situation. a union rep said he nodded out. different descriptions for what sleep researchers say sounds like a sleep attack.
>> when sleep intrudes involuntarily into the waking brain and seizes control of the brain so that the person who is doing their best to try to stay awake is overcome by exhaustion and fatigue.
>> reporter: whether on the rails or on the road an attack is usually a result of sleep deprivation . researchers estimate 2 million people nod off at the wheel each week. sleep is thought to be a factor in 7,500 traffic fatalities each year and likely contributed to the bronx bus crash that killed 15, the air crash that killed 50 and a freight train accident in iowa in 2011 that killed two. at the ntsb lab today we talked to chairman debbie hurzman.
>> fatigue is a problem. we have seen many freight rail , passenger rail and commuter rail accidents where if a the teaching has been a factor. sometimes working split shifts on the commuter side. sometimes working around the clock on freight operations, working through the night.
>> reporter: the ntsb has pushed for positive train control automatic braking systems. over industry objections, positive train control is set to become mandatory in two years. tonight the nypd and prosecutors are asking a difficult question.
>> there is a collaborative effort to determine if, in fact, this rises to the level of criminality.
>> reporter: whether falling asleep on the job is criminally negligent. tom costello, nbc news, washington.