My great grandfather (or was it my great, great?) was some exec with the Swiss railroad. I think this story came down from him. At least my mother told me this story, and attributed it to him. The line of transmission for some old family stories becomes blurred with time. Anyway, here is what my mother told me.
On a dark and foggy night the train chugged along the mountainside when the engineer began to notice an ominous image in the fog ahead. It appeared to be an angel beckoning him to stop the train. He called to his fireman to see if he had the same view. These two men rubbed their eyes and stared into the foggy night, they concurred that there was a definite image of an angel, persistently urging them to stop the train.
It seemed irresponsible to stop the loaded train halfway up the mountain, but the more they talked it over, the more they began to spook one another. Finally the engineer brought the iron horse to a stop. The image was still looming ahead of them in the fog. With its wings spread wide, the angel was demanding that they halt their progress. Just then the conductor came up the tracks from several cars behind the engine. "Hey, we're not scheduled to stop for several miles. What are you doing?"
"Don't you see that angel in the fog, there ahead of the train?" answered the engineer. "I'll take the responsibility for an unscheduled stop, but I just felt I had to stop."
"Oh, yeah. I see what you mean. Let me look up ahead along the tracks and see if I can find anything." agreed the conductor. He strode ahead along the tracks for a hundred or more feet when he suddenly stopped and let him mouth fall open. He ran back to tell the engineer what had happened.
As he approached the halted train, the engineer called out, "Hey Fritz, get back on the train. It was nothing. We found a dead moth was caught right inside the headlamp with its wings spread apart. In the fog it gave the eery appearance of an angel. You can tell your grandchildren how silly your engineer friend was when he saw that image in the fog."
"I will tell my grandchildren, alright, but it won't be about a silly engineer. Barely a hundred yards ahead of us the bridge is washed away!"