On the morning of December 1, 2013, a Metro-North Railroad Hudson Line passenger train derailed near the Spuyten Duyvil station in the New York City borough of the Bronx.

After reiterating its earlier conclusion that PTC would have prevented the accident entirely, it found the most direct cause was Rockefeller's inattention as the train entered the curve.

[1] Engineer William Rockefeller, a 15-year Metro-North veteran who had started as a clerk in the stationmaster's office at Grand Central and then spent 10 years as an engineer, was operating the train from the cab car, at the front of a consist of seven Bombardier-made Shoreliner passenger coaches,[3] in a mix of Metro-North and Connecticut Department of Transportation livery,[a] two of which were closed off and used only for deadheading by employees.

Under electromotor diesel power, it made all six of its scheduled stops in the upper, non-electrified portion of the Hudson Line in Dutchess, Putnam and Westchester counties without incident.

[b] Between Ossining and the last stop, Tarrytown,[2] just after dawn,[17] Hermann and Herbert swept toward the center of the train, where they met briefly.

They were positioning themselves for where Metro-North's rules required them to be, so Herbert could join Rockefeller in the cab and call out signals after the last stop, Harlem–125th Street.

Hermann, in the rear deadhead car with what he estimated to be six other employees, including Kelly, whom he had instructed to do so as the train's light passenger load did not require a third conductor, began doing his paperwork for the trip and preparing for his next.

"[19] Linda Smith, of Newburgh, who had boarded the train at Beacon with her sister Donna to see a choral performance at Lincoln Center, recalled that although she, too, was not fully awake, something seemed wrong.

In her passenger car, Linda Smith recalled the train turning sideways as the bumps she had felt gave way to bounces and seat cushions flew through the air.

The next day, the first regular business day back from the Thanksgiving holiday, it restored limited service as far south as Yonkers, three stations north of where the derailment occurred, with shuttle buses providing service to the Van Cortlandt Park—242nd Street subway station, the northern terminus of the 1 train into Manhattan.

[37] Westchester County offered free parking for the duration of the disruption in the lot it operates at the Valhalla station north of White Plains.

[45] Two days later, Federal Railroad Administration (FRA) director Joseph Szabo sent MTA head Thomas Prendergast a letter highly critical of the transit agency.

In the wake of the Spuyten Duyvil derailment, U.S. Rep. Sean Patrick Maloney, a resident of Cold Spring whose neighbor James Lovell was one of those killed, introduced legislation to make low-interest loans and guarantees available so that commuter railroads like Metro-North could implement PTC.

On a radio talk show following the crash, New York Governor Andrew Cuomo conceded that PTC is "controversial ... [some people say] it's not what it's cracked up to be."

Senators Richard Blumenthal of Connecticut and Charles Schumer of New York called on Metro-North to install cameras to monitor both the track and the engineers.

[31] After being lifted from where they had come to rest and restored to the track, the cars involved were impounded by the NTSB and taken to Metro-North's yards at Croton-Harmon and Highbridge.

[60] In early April, federal investigators revealed that after the accident, Rockefeller had been diagnosed with severe obstructive sleep apnea, a complication of his obesity,[61] which may have contributed to his loss of attention.

While Rockefeller had initially denied taking any such medications to investigators, his lawyer said that would not justify a criminal charge, a step the district attorney's office said it was still considering at that point.

It went on to fault Metro-North for not routinely screening for sleep disorders employees in positions defined by federal regulations as safety-sensitive, and the FRA for not requiring railroads to do so.

[65] Denise Williams, a dentist headed to a convention in the city who required back surgery for a fractured spine after she was trapped under a heavy passenger car for several hours, also gave notice through her attorney, who questioned among other things why the railroad had not replaced hundred-year-old track near the derailment site.

[66] Lawyers said it might be difficult for them to recover those amounts from Metro-North and the MTA if the cause of the accident turned out to be Rockefeller's lapse at the controls, since there would be far less liability on their part.

"One has to question whether the culture at Metro-North which led to the deaths of four people, should be investigated for criminal actions," said Russell's lawyer, who also faulted the MTA for not setting up a claims process in the wake of the accident, forcing those seeking compensation to litigate at increased costs both to themselves and the agencies.

Since that amount exceeded the limit per accident in the MTA's liability insurance, AIG was contracted to cover its future legal costs, as not all the claims and litigation have been resolved yet.

[65] After Metro-North had initially denied Rockefeller a disability pension based on the PTSD he suffered from the accident, he appealed, and in late 2016, Metro North announced that he would receive $3,200 a month.

[69] At the same time he received the pension, Rockefeller sued the MTA for $10 million in federal court, alleging the railroad had failed to install a system to alert engineers when the speed limit is exceeded.

[71] Executives also believed it was better to rely at least in part on the engineer remaining alert, citing a 2009 accident on the Washington Metro that was attributed to putting too much trust in technology found to be dysfunctional at the time.

In April 2019 the judge hearing the case dismissed the MTA's motion for summary judgement, ruling that Rockefeller had presented enough evidence that a juror could reasonably conclude his former employer was at fault.

[73] The office of Bronx District Attorney Robert Johnson reviewed the evidence gathered to see whether criminal charges, which could be as serious as negligent homicide, were warranted against Rockefeller.

[8] While criminal charges have been filed against the operators of vehicles in other recent deadly transportation accidents in and around New York City, and convictions have often resulted, defense lawyers said in this case it would be difficult to find a credible offense, since Rockefeller was exhibiting no clear sign of negligence such as alcoholism or cell phone use, and operating a vehicle while drowsy is not necessarily a crime.

In 2012, prosecutors argued that Ophadell Williams, the driver of a bus on which 15 passengers died on their way to a casino in Connecticut, had knowingly endangered lives by repeatedly driving without adequate sleep.