The Kinzua rail viaduct, in Pennsylvania, collapsed when it was hit by a tornado in 2003. First built in 1882 and redesigned 1900, it was at one time the highest bridge in the world.  The two video tracks in this album tell the story of the Kinzua catastrophe. The subsequent forensic investigation has cast new light on the failure of Tay rail bridge in Scotland 125 years earlier; with 75 people killed, the worst ever disaster to befall a trestle bridge.  This material forms part of the course T357, Structural integrity: designing against failure.