MOUNT JEWETT — A historic railroad bridge in northwestern Pennsylvania torn apart by a tornado in 2003 is now the site of a glass-bottom observation tower designed to give visitors a unique view of a gorge floor 300 feet below.

State officials held a ribbon-cutting ceremony Thursday for the new pedestrian walkway at Kinzua Bridge State Park in McKean County. The Department of Conservation and Natural Resources calls the park one of its key investments in the ecotourism region known as the Pennsylvania Wilds.

“We are excited that eight years after the historic railroad viaduct at Kinzua Bridge State Park was damaged by a tornado, visitors can experience, in a new way, what the structure once was, and also understand the power of the forces of nature that claimed a portion of it,” DCNR Secretary Richard J. Allan said.

The park features the remnants of the 2,053-foot long viaduct, or railroad bridge, first built in 1882. It was once considered the tallest and longest in the world, extending almost a half-mile over the Kinzua Gorge.

The bridge was rebuilt in 1900 to accommodate bigger and heavier trains and was used by freight traffic until 1959.