PHILADELPHIA -- In the moment the Amtrak train that derailed at a curve this week was supposed to be slowing down, it was accelerating, investigators said Thursday.
How that came to happen has emerged as the central question surrounding the derailment, which killed eight people and sent more than 200 to hospitals Tuesday night in the nation's deadliest train wreck in nearly six years.
In the minute or so before the crash, the train sped up from 70 mph until it reached more than 100 mph at a sharp bend where the maximum speed is supposed to be 50 mph, National Transportation Safety Board member Robert Sumwalt said. It's unclear, Sumwalt said, whether the speed was increased manually by engineer Brandon Bostian, who grew up obsessed with trains.
Investigators have found no problems with the track, signals or locomotive. Sumwalt said the train, on a route from Washington to New York City, was on time as it left the station in Philadelphia a few minutes before the crash.
Investigators want to know why the train was going so fast. But Bostian refused to talk to police on Wednesday, authorities said. On Thursday, Sumwalt said Bostian had agreed to be interviewed by the NTSB and the meeting will take place in the next few days.
Separately, the Philadelphia district attorney's office said it was investigating and will decide whether to bring charges. And an Amtrak dispatcher injured in the crash filed what's apparently the first lawsuit stemming from it, blaming Amtrak and seeking at least $150,000 in damages, his lawyer said.
Amtrak, in a statement posted online by CEO Joseph Boardman, called the derailment "a terrible tragedy" and said it was cooperating fully with the NTSB and was responding with every resource it has available.
"Amtrak takes full responsibility and deeply apologizes for our role in this tragic event," it said.
Bostian's lawyer, Robert Goggin, told ABC News that his client suffered a concussion in the wreck, needed 15 staples in his head and has "absolutely no recollection" of the crash. Goggin also said Bostian, who lives in New York, had not been using his cellphone, drinking or using drugs.
As the death toll climbed on Thursday with the discovery of what was believed to be the last body in one of the mangled railcars, Mayor Michael Nutter again appeared to cast blame on Bostian, questioning why the train was going so fast.
"I don't think that any commonsense, rational person would think that it was OK to travel at that level of speed knowing that there was a pretty significant restriction on how fast you could go through that turn," Nutter said.
Officials believe they have accounted for all 243 passengers and crew members thought to have been aboard, Nutter said. Forty-three remained hospitalized Thursday, he said.
ALL EIGHT VICTIMS IDENTIFIED IN DEADLY DERAILMENT
Officials and family have now identified all eight victims in the deadly derailment.
Laura Finamore, 47, of Long Island is the final victim to be identified. Family members say she was on the way back from a memorial service for a college friends' mother in Washington at the time of the crash.
Earlier Thursday authorities confirmed the identities of two other victims - Bob Gildersleeve and Giuseppe Piras.
Gildersleeve, a husband and father of two, worked for Ecolab for 22 years and lived near Baltimore, Maryland, a company spokesman said.
Giuseppe Piras was an Italian national.
Rachel Jacobs was the CEO of ApprenNet, a company that operates from the University City Science Center.
Her family released a statement Wednesday evening:
"This is an unthinkable tragedy. Rachel was a wonderful mother, daughter, sister, wife and friend. She was devoted to her family, her community and the pursuit of social justice. We cannot imagine life without her. We respectfully ask for privacy so that we can begin the process of grieving."
Co-workers say she left work early Tuesday night to catch the train.
"We had a work meeting and she left at 8:46 to get on at 9:00 and she texted her husband to say that she had got on the train," said ApprenNet employee Emily Foote.
Jacobs leaves behind a husband and a 2-year-old.
Also killed was 42-year-old Dr. Derrick E. Griffith of Brooklyn.
Dr. Griffith was the acting dean of student affairs at Medgar Evers College in Brooklyn, which is part of City University of New York.
Wells Fargo has also confirmed that one of their executives has been confirmed as one of the people who died in an Amtrak train derailment on Tuesday night.
The VP has been identified as Abid Gilani.
"It is with great sadness that Wells Fargo confirms that Abid Gilani, a valued member of our Commercial Real Estate division, has passed away. Our hearts go out to all those impacted by this tragedy," the company said in a statement.
A U.S. Naval Academy midshipman and an Associated Press staffer are also among those who are confirmed dead.
The midshipman has been identified as 20-year-old Justin Zemser of Rockaway Beach, New York.
"He was a loving son, nephew and cousin who was very community minded. This tragedy has shocked us all in the worse way and we wish to spend this time grieving with our close family and friends" said Susan Zemser, mother.
In a statement Thursday morning, the school said the midshipman was on leave and on the way home when the train derailed.
Zemser was a member of the 17th Company, an English major and an academic honor student at the Academy. He was a member of the Navy Sprint Football Team, the Jewish Midshipman Club, and the Semper Fi Society (a Marine Corps club).
Meanwhile, the Associated Press said staffer Jim Gaines, a 48-year-old father of two, was also among the victims.
His wife, Jacqueline, confirmed his death.
The AP said Gaines had attended meetings in Washington and was returning home to Plainsboro, New Jersey.
Gaines joined the AP in 1998 and was a key factor in nearly all of the news agency's video initiatives, the AP said, including a service providing live video to hundreds of clients worldwide.
He is also survived by a 16-year-old son, Oliver, and an 11-year-old daughter, Anushka.
Stories of survival
In the midst of this tragedy are also stories of survival including former Pennsylvania congressman Patrick Murphy who was on board the train.
He was on his way home from a business trip to Washington D.C.
Murphy, an Iraq war veteran, says he never experienced anything quite like that.
"Next thing you know, the car geared to the left at first and finally over to the right. I'm 6'1" and about 200 pounds but I was thrown like a rag-doll like everyone else," said Murphy.
Murphy suffered a few bumps and bruises but says he feels fine.
We also spoke with a passenger Jeff Cutler who lives in Brooklyn but grew up in West Oak Lane.
He took a hit to the head and leg as his train car tumbled but all things considered, Cutler says he is a grateful man.
"It was enough of a concern that they wanted to x-ray it. I'm mobile and I can walk - a slight limp - but there is no break. I'm luck I'm standing here," said Cutler.
The Associated Press contributed to this report.