It's an interesting puzzle.
If the object was light enough that a half dozen guys could pick it up, I could see them doing that and putting it on the west (unused) set of rails. But they wouldn't carry it away entirely; that's the job of the crash investigators. When a news photographer got there later that day and shot the scene, the papers carried a picture of an unimposing chunk of aluminum sheet between the rails, looking like twenty pounds tops. If an engine had been there to shoot, they sure would have taken that. And the chunk of aluminum sheet was way too small to be the object lying on the east tracks in the overhead shot.
The railroad guys are experts at clearing tracks, picking up stuff and moving it. Probably have a small flatcar with a jib boom on it, the railroad equivalent of a pickup truck, for jobs like this. Once they had the go-ahead from investigators, it was probably a ten or twenty minute job.
When you add in the whole missing-engine conundrum as I laid it out in an upcoming chapter and uploaded standalone as
https://we.tl/2iOuz04If7, the simplest explanation is that the number four engine was blocking the track. But the evidence is thin.