The woman who died in the Hoboken train crash has been named as 34-year-old Brazilian Fabiola Bittar de Kroon.
The IT worker and mother-of-one was not a passenger on the train that crashed through ticket barriers on Thursday, but was killed by debris that fell on to the platform.
Investigators have found one of the train’s black box recorders but debris has so far blocked access to the other.
More than 110 people were injured in the accident, some critically.
The black boxes hold data including the train’s speed, throttle position and brake use.
Ms de Kroon had recently moved to New Jersey from Brazil after her husband took a job with an international drinks company.
She had just dropped her toddler daughter off at a childcare centre before rushing to catch a train, the centre’s director said.
Her mother Sueli Bittar described her as a “beautiful girl inside and out”, ABC News reported.
The investigation into the crash is expected to take between a week and 10 days, officials from the National Transportation Safety Board (NTSB) said.
Driver Thomas Gallagher, 48, has been released from hospital and is said to be co-operating with the inquiry.
New Jersey Governor Chris Christie has said there was no indication the crash was “anything but a tragic accident”.
Hoboken is across the Hudson River from New York City. Many commuters use the busy station to travel into Manhattan.
NTSB officials have said they will look into whether there were any similarities between Thursday’s crash and one at the same station in 2011 that injured 34 people.
An NTSB investigation found excessive speed to be the main cause of the 2011 accident.
US rail safety
But most rail companies were unable to meet the deadline as the system is expensive and complex to install. Some rail lines – including New Jersey Transit – threatened to shut down completely if it was enforced. In response, Congress extended the deadline to install PTC systems to 2018.
Rail lines can then apply for an additional two-year extension to finalise updates and test the system. But safety targets for New Jersey’s commuter trains say PTC installation should be completed by 2018.
According New Jersey Transit’s most recent PTC progress report, none of the 440 trains on the New Jersey Transit rail line are equipped with PTC, nor have any employees been trained to use the equipment.
PTC safety systems are designed to automatically override the actions of train engineers if the locomotive is travelling too fast. In effect, they act as a safeguard against “human error” which could cause derailments or collisions.
The system uses wi-fi, GPS and a specific coding system to relay real-time information from trains to control centres.
Last year, the Guardian reported that US trains were far behind those in Europe, which have had automatic safety systems for years.
Recent deadly passenger train crashes in the US
While the US sees its fair share of deadly freight train crashes and derailments, this is the first deadly passenger train crash for five months.
April 2016; Chester, Pennsylvania: two die and 31 injured as a train collides with a diggerMay 2015; Philadelphia, Pennsylvania: a train travelling between Washington and New York City derails – eight people die and 200 of the 243 people on board are injuredFebruary 2015; Oxnard, California: passenger train hits vehicle on the tracks – the train driver dies and 29 people are injuredFebruary 2015; Valhalla, New York: passenger train hits a car in suburban New York City, killing six train passengers