Thanks for the additional information, fellows. Fog or snow explains a lot.
Fog . . . I share your pain, Big Jim. My home seniority district was the Los Angeles Division. The Third District between Riverside and Los Angeles, and the Fourth District from Fullerton to San Diego were typically foggy every night in the spring and fall, and many winter and summer nights also. Sometimes we had fog so heavy that we could only see the track every now and then, and that's no exaggeration. In the early 1980's I had a regular assignment in passenger service on San Diegans, where there were seven intermediate passenger stops (and at least a couple of meets on single track) with a district speed of 90 MPH. The train crew had to give a highball at passenger stops using the communicating whistle, as they were somewhere back on the station platform, out of sight back in the fog. You just have to know the railroad, keep your side window open and listen to everything you are passing, and not make small talk in the cab. The great uncertainty was, "Who is out there on opposing trains, and do they know where they are?"
For a couple of months, I worked the night Corona road switcher, in the fog of course. We switched set-outs at Porphyry, did industry switching, and switched cars for through trains to pick up. They did not have many hand-held radio packets then, so, when fog set in the Trainmen used fusees to pass signals. When it got too thick for that, they used police whistles: two tweets, shove forward at 3-4 MPH; three tweets, back up at 3-4 MPH; one long tweet, stop. I had my head out the window listening for police whistle signals.
Not intending to hi-jack this thread, but -- if fog or snow was a factor -- there is no way to know what might have distracted the N&W passenger Engineer and contributed to his losing his place in the snow or fog. It might not take much -- some small mechanical thing, the engine frequently trying to slip on wet rail, something falling down inside the cab, pouring coffee from his thermos, etc.