No nukes that I ever saw on the LA Division, though that doesn't mean there weren't, just not enough I ever saw any. But, I've handled lots of bombs (before and after Roseville) and even a few missiles (do not hump!).

Before Roseville, the bombs were handled in those very obvious placarded DODX piece of crap 1943 cars wit wood floor, with friction bearing trucks, and with what appeared to be no real visible attempts at any kind of security.

After, in brand new all steel roller bearing boxcars, which had a lot more folks keeping an eye on them, and these were not as easy to identify as "bomb cars", as the DODX pieces of junk had been.

The few times that I handled what I believe were Titan missiles, they always came with an extra caboose and/or two (usually UP cabooses IIRC?) next to the missile car, in the train and/or cut, with lots of Air Police on-board, with real M-16's and side arms.