![Photo of Smithfield Street Bridge, Pittsburgh, Pa. (Credit: Brook Ward, Creative Commons license 2.0.)](../sites/default/files/styles/full_width_image_700x400max/public/media/images/2018/smithfield_bridge_credit_brook_ward_cc2.jpg%3Fitok=zJHNjLOi)
Photo of Smithfield Street Bridge, Pittsburgh, Pa.
![Photo of Smithfield Street Bridge, Pittsburgh, Pa. (Credit: Brook Ward, Creative Commons license 2.0.)](../sites/default/files/styles/full_width_image_700x400max/public/media/images/2018/smithfield_bridge_credit_brook_ward_cc2.jpg%3Fitok=zJHNjLOi)
An official website of the United States government
Official websites use .gov
A .gov
website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites..