The Collapse of the Kinzua Viaduct

Kinzua Viaduct was built over Kinzua Creek gorge in north-central Pennsylvania in 1882 to expedite coal delivery to the Great Lakes. Completely rebuilt in 1900, this National Historic Civil Engineering Landmark stood until Jul 21, 2003, when a tornado brought 23 of its spans and 11 of its towers down. Leech performed forensic engineering analysis on the fallen structure and determined that a combination of design oversight, material fatigue and corrosion was key to the failure.