This is a piece of the sea wall that has been devoured by Gribbles, an underwater worm that has been eating away at the base of the viaduct. (Jim Gates)

America's Infrastructure: The Alaskan Way Viaduct

This is a piece of the sea wall that has been devoured by Gribbles, an underwater worm that has been eating away at the base of the viaduct.

Credit: Jim Gates