Article Photos: Pa. zoo: Wild dogs killed boy who fell in exhibit 18/21

  An electronic display sign near the entrance for the Pittsburgh Zoo and PPG Aquarium shows the zoo is closed on Monday, Nov. 5, 2012, in Pittsburgh. Zoo officials said a young boy was killed after he fell into the exhibit that was home to a pack of African painted dogs who pounced on the boy and mauled him on Sunday, Nov. 4, 2012. (AP Photo/Keith Srakocic)