[Ol' Dan Tucker]

Or can something like this occur over time and wasn’t present then?

I think it's just something endemic to the area.

There are 257 sinkholes in a one-mile radius of the museum. (See: http://www.plotscan.com

[nascarnation]

Interesting info - thank you!
I hope they are able to get this repaired without going broke.
I know they are also in the process of building a new race track next door.