The lawyer said the next thing the engineer remembered was coming to, looking for his bag, retrieving his cellphone and calling 911 for help. He said the engineer's cellphone was off and stored in his bag before the accident, as required.
"As a result of his concussion, he has absolutely no recollection whatsoever of the events," Goggin said. He said he believes the engineer's memory will probably return once the head injury subsides.
Goggin said that his client "cooperated fully" with police, immediately consented to a blood test and surrendered his cellphone. He said he had not been drinking or doing drugs. Police had said Wednesday that the engineer had refused to give a statement to law enforcement.
Robert Sumwalt of the National Transportation Safety Board said Bostian has agreed to speak to NTSB investigators in the next few days.
Goggin said his client was distraught when he learned of the devastation.
A data recorder and a video camera in the train's front end were recovered from the wreck and could yield clues to what happened. Amtrak inspected the stretch of track on Tuesday, just hours before the accident, and found no defects, according to the Federal Railroad Administration.
The engineer hit the emergency brakes moments before the crash but slowed the train to only 102 mph by the time the locomotive's black box stopped recording data, according to Sumwalt. The speed limit just before the bend is 80 mph, he said.
NTSB investigators said Thursday evening that they had determined the Amtrak train sped up for a full minute before it derailed at a sharp curve.
Sumwalt said a camera mounted on the front of the train shows it was going 70 mph 65 seconds before the video went dark.
By 16 seconds before the crash, the train had increased to 100 mph, soon reaching 106 mph right before entering a 50 mph section.
Investigators are still unsure why the train was speeding up.
Sumwalt says inspection records show no anomalies with the track, signals or train itself. It had left Philadelphia's 30th Street Station on time.
Nutter said the engineer was clearly "reckless and irresponsible."
"Part of the focus has to be, what was the engineer doing?" he said. "Why are you traveling at that rate of speed?"
After facing a backlash over those comments, Nutter told reporters on Thursday that he "was being expressive," and just saying what others across the city were likely thinking.
The train, heading from Washington to New York, derailed in a decayed industrial neighborhood not far from the Delaware River just before 9:30 p.m.
Eighteen people remained at Temple University Hospital, but all were expected to recover, said Dr. Herbert Cushing, chief medical officer. The patients are 19 to 80 years old and have severe rib injuries, he added.
Others who were injured during the derailment are being treated at nearby medical facilities.
The dead included an Associated Press employee, a midshipman at the U.S. Naval Academy, a Wells Fargo executive, a college administrator and the CEO of an educational startup.
It was the nation's deadliest train accident in nearly six years.
With the investigation underway, all Amtrak service has been suspended between Philadelphia and New York, forcing many thousands of commuters and other travelers to find some other means of transportation.
Despite pressure from Congress and safety regulators, Amtrak had not installed along that section of track positive train control (PTC), a technology that uses GPS, wireless radio and computers to prevent trains from going over the speed limit. Most of Amtrak's Northeast Corridor is equipped with PTC.
"Based on what we know right now, we feel that had such a system been installed in this section of track, this accident would not have occurred," Sumwalt said.
Amtrak's Boardman said in a statement to the press Thursday that all trains in the Northeast Corridor will be equipped with PTC technology by the end of the year.
"Today I'm committed to meeting the requirement of positive train control," Boardman said.
The tight curve is not far from the site of one of the deadliest train wrecks in U.S. history: the 1943 derailment of the Congressional Limited, bound from Washington to New York. Seventy-nine people were killed.
Amtrak carries 11.6 million passengers a year along its Northeast Corridor, which runs between Washington and Boston.
Al Jazeera and wire services