Credit: NTSB

Answers on why Amtrak 188 crashed one year ago today in Philadelphia, killing eight and injuring dozens more, could come by next week.

The National Transportation Safety Board will release its final report on the crash “in another week or so,” former Mayor Michael Nutter, who was still in office when the train derailed last year, told Billy Penn in an interview.

“I think it is fairly standard in these situations that a full and complete NTSB investigation usually takes a year, whether it’s trains or airplanes that crash,” Nutter told Billy Penn, part of a conversation about the derailment that will be published later today. “All these significant scenes take a year. They’re very good at what they do but they’re very thorough. I’m very very interested just to understand what happened.”

The NTSB has released interim reports marking its progress on the investigation into the Amtrak 188 crash that have included photos, evidence, interviews with key players and more. But the federal body has yet to nail down a conclusive reason for why the Northeast Corridor train derailed at the Frankford Junction on May 12, 2015.

Just days after the crash last spring, NTSB officials had concluded the train, bound for New York, was traveling at a speed of more than 100 m.p.h., or nearly twice what the posted speed limit in the area was, as it traveled around the bend in Philadelphia. They also said had Amtrak installed a technology called Positive Train Control — which automatically slows trains moving too fast — in the area, the crash could have been prevented.

As of the last interim report by the NTSB, train engineer Brandon Bostian was interviewed at least twice by federal investigators. In his first interview the week of the crash, Bostian said he had few memories of the night. But in a follow-up interview six months later in November, Bostian, who suffered a head injury during the crash, seemed to have remembered more steps he took moments before the train derailed.

“I couldn’t say with certainty that my memory is accurate,” he told investigators in November. “There are a couple of prominent scenes in my head that have come back to me since we last spoke.”

The engineer, in his second interview with investigators, said he was actually operating the train 10 m.p.h. slower than what was the posted speed limit, and he remembers pushing the throttle forward to get closer to the speed limit. He also recalled three separate steps taken to try to slow down the train, from a “ten pound” brake application, to a “full service” brake to putting the train in “emergency” mode to get it to stop.

Bostian has not been criminally charged in connection with the crash, though some lawyers and experts have speculated that he could based on what the NTSB concludes in its final report.

During a post-crash interview on CNN, Nutter famously said, “you’d almost have to be an idiot” to speed up the train to make up for lost time, as early reports had indicated Bostian may have done. His tone has softened a bit since then.

“I’ll leave the law enforcement issues to the law enforcement community. I expressed my personal feelings as a citizen, as a father, as a human being. Obviously something went wrong, terribly wrong. I’ll leave it to investigators. I expressed a human feeling.”

The document to be released next week could have a seismic impact for the dozens of people who filed lawsuits after the crash, whether it was because they were injured on the train or a family member was killed. All of those lawsuits — there are more than 60 — were consolidated and will be heard in Philadelphia.

Chris Krewson is the executive director of LION Publishers, a national nonprofit association that serves local journalism entrepreneurs build sustainable news organizations, and the founding editor of...