DONORA, Pa.—For decades, visitors and industry crossed into the heart of Donora on a bridge spanning the Monongahela River.

But the 108-year-old bridge, deemed unsafe, closed in 2009, and state officials say it can now barely support its own weight. Pennsylvania has more structurally deficient bridges than any other state in the nation, and with a $2 billion budget deficit, it is tearing down some that don’t seem worth repairing. The Donora-Webster Bridge is next.

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