In the final 60 seconds before Amtrak 188 derailed, the train accelerated from 75 mph to more than 100 mph, the National Transportation Safety Board (NTSB) reported Thursday evening.
However, no official cause of the crash and why the train accelerated has not yet been determined, said NTSB board member Robert Sumwalt.
All equipment on the train is being examined for anomalies but none have yet been detected, he said.
Newly identified among the dead on Thursday were Laura Finamore, 47, a Manhattan realtor, Italian businessman Giuseppe Piras, Derrick Griffith, the dean of student affairs and enrollment management at Medgar Evers College in Brooklyn, and Bob Gildersleeve, an executive with a food-safety-hygiene company, who was found in the train's wreckage on Thursday by a cadaver dog.
Previously identified as fatalities were Associated Press employee Jim Gaines, 48, New York resident and Philly tech CEO Rachel Jacobs, 39, U.S. Naval Academy cadet Justin Zemser, 20 and 55-year-old Wells Fargo VP Abid Gilani.
All 243 people aboard Amtrak #188 have now been accounted for, officials said Thursday.
The National Transportation Safety Board previously said that they determined the train was traveling at 106 mph in a 50 mph speed limit zone and that the engineer hit the emergency brake as the train took a left curve.
The NTSB will soon interview the train's engineer, Brandon Bostian, 32.
"We want to know what he recalls of that tragic event. And then he can paint a picture of what happened," Sumwalt said.
Bostian's attorney, Philadelphia lawyer Robert Goggin, told ABC's Nightline that Bostian is "distraught" and cannot remember the derailment. Bostian suffered a concussion, leg injuries and a head wound requiring 14 staples in the crash, but survived.
Amtrak has said it will install positive train control, technology that restricts train speed per speed limits, on all rails by the end of 2015.
"Positive train control would have prevented this accident," Sumwalt said Thursday.
Amtrak service from Philly to NYC and the Regional Rail's Trenton line are still discontinued.