Last Updated May 14, 2015 10:18 AM EDT
The attorney for Brandon Bostian, the engineer for Amtrak Train 188, told ABC's "Nightline" his client has no memory of the deadly crash that killed at least seven people, CBS News' Kris Van Cleave reports.
"He remembers driving the train, he remembers going to that area generally, has absolutely no recollection of the incident or anything unusual," Bostian's attorney Robert Goggin said.
Bostian, who lives in Queens, New York, has been an Amtrak engineer since 2010. After the crash, he was treated for injuries. His lawyer told ABC News that Bostian suffered a concussion, leg injuries and a cut in his head that needed 14 staples to close.
He was then taken to a police station, where he declined to make a statement before leaving with his lawyer. As of Wednesday, he had yet to speak with National Transportation Safety Board investigators.
"We've not interviewed the engineer, but I want to point out that for somebody who's been through a traumatic event, this is not at all unusual for human behavior to have the mind blank out things like that, at least for the short term," the NTSB's lead investigator, Robert Sumwalt, said.
The NTSB said the train was traveling at 106 mph where the track curves, more than double the speed limit for that section. Bostian applied the emergency brakes moments before it derailed, but it did little to slow the train down.
Philadelphia Mayor Michael Nutter said there is no reason the engineer should have been traveling that fast.
"Clearly he was reckless and irresponsible in his actions. I don't know what was going on with him, I don't know what was going on in the cab, but there's really no excuse that could be offered," Nutter said.
Sumwalt said he's "not going to agree with that at all."
"I think that's a subjective, judgmental statement," he said. "We're here right now just to find out what happened, and that's what we want to do. We want to find out what happened and why, and we're not casting any judgment because at this point right now we want to talk to this person and find out what his perspective was."
Surveillance video shows the train moments before it went off the tracks. The camera captured the electrical sparks from the crash.
Sumwalt said trains go over the curve at Frankford Junction many times a day and don't derail. This case was different.
"Here we got one that's doing twice the speed, and it derails," he said.
On Wednesday, rescuers expanded the search area looking for those still unaccounted for.
Crash survivor 30-year-old George Alexeiades suffered injuries to his right arm. He remembered the chaos inside the train.
"There was a girl that landed, ended up, where you put your luggage. She hit her head and ended up there, and I had to help her down," Alexeiades said. "I just still can't believe that I was on that train."
Amtrak has been in the process of installing a system that could have automatically slowed the train down if it was speeding, but it had not been applied to the set of tracks where the train derailed. The NTSB said the technology could have prevented this very type of accident.