TRINIDAD, Colo. (CBS4)– Drivers are taking the scenic byway from Trinidad to the Sangre De Cristo mountains, but not always by choice.

A partial collapse of a bridge on Colorado Highway 12 west of Trinidad over the Purgatorie River has closed the highway.

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The Colorado Department of Transportation said part of the bridge deck cracked and broke away.

No one was on the bridge or under it when the two-foot section fell off.

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The aging bridge was already under re-construction because it was old although the cause of the bridge failure is being investigated.

The current detour directs drivers through Walsenburg on U.S. 160, west of Highway 12 and south on 12 through La Veta.

CDOT said they’re hopeful the replacement detour will be ready by Friday afternoon or Saturday morning.

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The bridge is located about 22 miles west of Trinidad, about one mile west of the Town of Weston. It was built in 1925.