UPPER DARBY, Pa. - Police say a "tragedy" in Upper Darby resulted in the death of a teenager Friday night.The teen was shot and killed by a single gunshot on the 6900 block of Ruskin Lane, according to a tweet by Upper Darby Police.Police say they believe the deadly shooting stemmed from children playing with a family member's gun.Police are asking families to "educate your children."The shooting is under investigation..