Movies didn't kill it, rather the Great Depression:
> By the 1930s, staged train wrecks were starting to lose their popularity because wrecking old but otherwise useful locomotives was seen as wasteful at the height of the Great Depression.
Also:
> ...staged train wrecks were a popular—albeit destructive—event at fairs and festivals across the U.S., long before anyone ever thought of wrecking old automobiles at a demolition derby or monster truck rally.
Not to mention the various incantations of robot wars. People still want to see things in real life go boom.
No doubt you can find contemporary journalists saying "wasteful in this depression!" if you look. And probably others saying "wasteful!" in every decade... how can we tell whether this was the reason?
I know stunts with WWI surplus airplanes were a common attraction in the 20s, maybe trains just started to seem old-fashioned?
Movies also sounds likely, to me, they were coming of age. In fact IIRC booming, as cheap entertainment.
> By the 1930s, staged train wrecks were starting to lose their popularity because wrecking old but otherwise useful locomotives was seen as wasteful at the height of the Great Depression.
Also:
> ...staged train wrecks were a popular—albeit destructive—event at fairs and festivals across the U.S., long before anyone ever thought of wrecking old automobiles at a demolition derby or monster truck rally.
Not to mention the various incantations of robot wars. People still want to see things in real life go boom.