Boom: A controlled explosion went off this morning shortly after 6 a.m. on the hillside overlooking West Carson Street on the South Side. Norfolk Southern officials are evaluating their next steps after the blast failed to bring down as much material as they had hoped from the unstable hillside. (Photo by Darrell Sapp/Post-Gazette) #Pittsburgh #PGH #412 #explosions #Pittsburghexplosions #SouthSidePGH #NorfolkSouthern