My parents told a story, they lived in Vegas, Dad worked at Nellis. A train goes by and Mom says "What are those? They look like little lead caskets" -4 people in the car incl Dad's brother. WIthin DAYS the FBI was interviewing people in Dad's hometown (OK) and the local pawn shop who gave Dad a heads up. (the TV went back and forth to the pawn shop because Crap tables)
The internet is far older than they say. There was no possible way to do all that background the old fashioned way in 1957.
Problem: They had sworn to John Q. Public that they would never ship atomic/nuclear materials via rail. But then they did. Nobody in that car had a clue.
Long time family story. I know it by heart.
Nobody in that car spoke to another person about it, it was just an offhand observation.
Presumably it happened on a Friday because that was test day.
They were shipping the stuff to Philly.