In a preliminary report on the derailment of Amtrak's Train 188, the National Transportation Safety Board said on Tuesday that it had found no anomalies with the braking system of the formation or the signals and track at the crash site, USA Today noted.

Data from an event recorder, however, "indicated that the engineer activated the emergency brakes seconds before the derailment," the NTSB report detailed.

Eight passengers were killed and more than 200 riders injured when the train's locomotive and all seven passenger cars went off the tracks on May 12 north of the Philadelphia's downtown area. The formation might have been traveling at more than 100 miles an hour as it entered a sharp curve, even though the the Federal Railroad Administration has set a 50-mile-per-hour speed limit in the section of track, the Wall Street Journal had noted in the immediate aftermath of the incident.

The train engineer in charge of Train 188 insisted that he "has absolutely no recollection of the incident or anything unusual" and "no explanation" for what caused the accident, according to statements his his lawyer made to ABC News. Brandon Bostian, 32, of Queens, New York, was "very distraught" after learning the crash caused several fatalities, his attorney Robert Goggin told the network.

As part of the investigation, NTSB officials said they were continuing to look into Bostian's cell-phone records; the engineer told investigators that the device was in a bag at the time of the derailment, according to the Washington Post.

"Investigators are in the process of correlating the time stamps in the engineer's cell phone records with multiple data sources including the locomotive event recorder, the locomotive outward facing video, recorded radio communications, and surveillance video," the federal agency noted on Tuesday.

The NTSB admitted it was having difficulties as it tried to determine whether the phone was in use while Bostian was operating the train because its text-message and voice logs have time stamps from different time zones, the newspaper detailed. Investigators noted, however, that Bostian has cooperated with the inquiry and provided the password to the device.