A historic railroad bridge, the Kinzua Viaduct in Pennsylvania, that was once the longest and tallest in the world and remained the fourth-tallest in the country will not be rebuilt because the project would be too expensive, state officials said.

Officials with Gov. Ed Rendell's office and the Pennsylvania Department of Conservation and Natural Resources said the state has opted against attempting to raise the 121-year-old Kinzua Viaduct, which was mostly toppled by a tornado on July 21.

Rendell spokesman Abe Amoros said the state could not afford the estimated $45 million to rebuild the bridge, which stretched almost a half-mile and towered 301 feet above a gorge near the Allegheny National Forest, about 110 miles northeast of Pittsburgh.

Rendell's decision is supported by the state Department of Conservation and Natural Resources, which owned the Kinzua Viaduct, part of a state park that bore its name, said spokeswoman Gretchen Leslie.

The Kinzua Viaduct