Young man killed while playing Pokemon at tourist attraction

SAN FRANCISCO - A college student has been shot to death while playing "Pokemon Go" at a tourist attraction in San Francisco.Authorities say 20-year-old Calvin Riley was shot Saturday night by an unknown assailant at Aquatic Park near Ghiradelli Square.The U.S. Park police and local homicide detectives are investigating what led to the shooting.A family friend told KGO-TV Riley and a friend were playing the popular mobile game when someone came up and shot the young man in the back and ran away.