Bostian initially told the NTSB he had no memory from a few minutes before the crash until after it had happened. (His lawyer said so publicly as well.) By the second interview, Bostian—who had been concussed in the wreck—remembered a few more details but still not the complete sequence.

On the track ahead of the site, there’s a straightaway where a train of the type Bostian was driving can go up to 80 miles per hour, before decreasing significantly for the sharp turn where he derailed. Here he narrates what happened:

The memory I think I may have from that night was that I came out of the 65 mile an hour curve. I pushed the throttle forward to accelerate my train. And as I approached 70 miles an hour, I have a memory that I backed off the throttle by mistake because I was targeting 70 miles an hour instead of 80 miles an hour. And as I approached 70 miles an hour, I have a memory that I took action to bring the train up to 70 miles an hour. And I have a memory that I realized my mistake, that I should have been operating at 80 miles an hour. And that I pushed the throttle forward in order to accelerate from 70 to 80.

Instead of braking after that as the curve approached, however, the locomotive data recorder shows the train just kept accelerating. “I don't remember anything from that point until after the train was already in the curve,” Bostian said, describing everything from there until he started braking as “dream-like.”

If that sort of detail sounds dry, it’s among the more gripping material in the tranche, most of which is technical data. Investigators also quizzed Bostian about his training, his sleep habits, his daily schedule, and even how he got to work. There’s one small portion in one interview that is off the record, for unexplained reasons.

Bostian said the locomotive had engine problems, but nothing significant. (“All of our engines have minor issues.”) He complained of wind noise from one window, but nothing serious. One theory shortly after the crash was that Bostian may have been distracted by rocks or bullets. A SEPTA train had been hit with a rock, apparently badly, that night, with its windshield shattered. Bostian passed the train, which had come to a stop, and blew his whistle hard, but when NTSB investigators asked him whether he was worried—practically invited him to blame it for the wreck—Bostian largely demurred:

Q. Okay. Do you recall being concerned for your own safety? A. I was a little bit concerned for my safety. There's been so many times where I've had reports of rocks that I haven't seen anything, that I felt like it was unlikely that it would impact me. And I was really concerned for the SEPTA engineer. I had a co-worker in Oakland that had glass impact in his eye from hitting a tractor-trailer and I know how terrible that is. Q. Okay. So you were concerned for SEPTA. I’m sorry, were you concerned for yourself, that this may also happen, possibly? A. Slightly. But I figured there's a good chance that they left. Whoever was throwing rocks and shooting probably had left. I wasn't, you know, super concerned, I don't think.

In a strange echo, an Amtrak Acela passing through Philadelphia was struck by an object that shattered its window Monday.