ID Large lit ground object in KY/TN?

Here's the story: we were flying American Airlines from St louis to RDU
(Raleigh/Durham) last night (12/27, about 9:30 CT. About half way
through the flight I noticed a large shape outlined by lights, oriented
east to west. The lit outline looked like this.


*************************
* *
* *
* *
* *
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(connect the dots)

The point was to the east, the southern part (below the point) looked
bigger than the part north of the point. It was to the east/northeast
of a sizable town and looked to be about the size of small town, there
were no lights visible within the shape so it probably wasn't a mall or
the like.

I'd guess it was near Bowling Green KY, but I could be 100s of miles
off.

Like most pilots here, I can usually identify objects on the ground,
but this one has me puzzled. Are any local pilots able to identify it?

Thanks