At the Pittsburgh International Airport, Consol Energy will begin extracting gas — even under the runways. MeRyan/Wikimedia Commons hide caption

itoggle caption MeRyan/Wikimedia Commons

The headquarters for University of Pittsburgh Medical Center and Highmark Blue Cross/Blue Shield dominate the Pittsburgh skyline much as they organizations have dominated health care in the region for decades. Jeff Brady/NPR hide caption

itoggle caption Jeff Brady/NPR

A security guard closes the gate at the Pittsburgh Zoo, where a 2-year-old boy was killed Sunday. John Heller/AP hide caption

itoggle caption John Heller/AP