Thursday's fatal train crash in Hoboken, New Jersey, left one woman dead and more than 100 others injured. A system called positive train control may have prevented it.
Positive train control (PTC) is an added safety system that monitors and controls train movements.
It's similar to today's self-braking cars, with technologies built to anticipate an accident and avoid fender-benders -- or worse.
New Jersey Governor Cuomo refused to speculate whether PTC could have prevented the crash.
"The positive train control system no doubt can be a benefit, depending on the circumstances," Cuomo said. But "before we start to prescribe what could be a solution, you really have to define the problem," he said.
User Leon O (@monduras) shared this video of the wreckage on Twitter.
Governor Chris Christie said the train was moving so fast it jumped the track. Unclear why.
NTSB is gathering information on Hoboken train crash.— NTSB_Newsroom (@NTSB_Newsroom) September 29, 2016
The National Transportation Safety Board (NTSB) is looking into the cause of the crash.
What's with the delay?
All trains were scheduled to have operational positive train control systems by the end of last year, but Congress extended the deadline to avoid a possible shutdown of the nation's railroads.
Congress pushed the deadline back to the end of 2018.
"Every PTC-preventable accident, death and injury on tracks and trains affected by the law will be a direct result of the missed 2015 deadline and the delayed implementation of this life-saving technology," NTSB Chairman Christopher Hart said earlier this year.
One user questioned the technology gap between cars and trains.
In November 2015, an Amtrak passenger train traveling faster than the advised speed limit derailed in Philadelphia.
Eight people were killed and more than 200 others were injured. The NTSB said PTC would have prevented it.
Any other solutions?
Some critics are wary of implementing PTC for all trains, because it would be too costly.
Freight rail companies spent nearly $6.5 billion to develop PTC and required more than 2,000 personnel to install it., according to the Association of American Railroads.
Others have also suggested placing a second conductor in the driver's seat.
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