A construction crew working in Lawrenceville discovered a cache of buried cannonballs today at the site of an old civil war arsenal, according to Pittsburgh police. The construction crew building apartments across the street from Arsenal Middle School near 39th and Butler streets discovered between 35 and 43 cannonballs, a company spokesman said. (Photo by Darrell Sapp/Post-Gazette) #Pittsburgh #PGH #412 #history #Pittsburghhistory #cannonballs #civilwar #civilwararsenal #Lawrenceville #PGPhotos