World Trade Center aluminum
This crumpled piece of exterior sheathing from the World Trade Center was recovered from the debris pile. Context:
The twin towers of the World Trade Center, a New York City landmark and the tallest buildings in the world when completed in 1973, were noted for their incredible 110-story height and their gleaming exterior. The towers were clad in an aluminum alloy sheathing that gave the buildings a golden sheen at sunrise and sunset. The material covered the closely-spaced exterior steel columns, enhancing their soaring appearance.