NEW YORK (Reuters) -- Federal investigators on Monday released thousands of pages about the fatal derailment of an Amtrak passenger train last year in Philadelphia, but the central mystery of what caused the crash remained unexplained.
The documents, posted online by the National Transportation Safety Board, include interviews with the train's engineer, Brandon Bostian, who told investigators he had no recollection of the moments before the accident.
An Amtrak regional train headed from Washington, D.C., to New York, went off the tracks on May 12 along a northbound curve in Philadelphia while traveling at more than twice the 50 mile-per-hour (80 kilometer-per-hour) speed limit. Eight people were killed and more than 200 injured in the incident.
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The documents represent every fact that the various agencies involved in the investigation, including the NTSB, Amtrak, local emergency responders and rail worker unions, have agreed upon.
%shareLinks-quote="The findings appear to rule out several possible causes as investigators found no evidence of malfunction in the locomotive, tracks or signals." type="spreadWord"%
The NTSB has previously said Bostian was not talking or texting on his phone at the time of the accident. His lawyer has said Bostian had turned off his phone, as required by federal regulations.
The documents released on Monday contain no "smoking guns," according to an NTSB official. Their release marks the end of the agency's fact-finding phase.
Investigators are now focused on identifying the probable cause of the crash. That analysis will be included in a final report that will likely be reviewed by the NTSB in the spring.