by terry03
There is a viaduct that crosses Walnut Creek just to the west of Erie, Pa. on the Norfolk Southern. Is this the Viaduct they call "Thornton Junction Viaduct"?
Thornton Jct. was quite a ways west of Erie, actually just west of Lake City.
Elk Creek was between Lake City and Thornton Jct., and the NKP trestle that spanned the valley did have a partial collapse c. 1970.
The Conrail viaduct (old masonry arch structure) over Elk Creek also had a partial collapse c. 1980's.