Sue Klebold talks about her relationship with her son Dylan and what she went through during and after the tragedy. -- SUBSCRIBE to ABC NEWS: .brKlebold said she had no idea her son, who she used to call her Sunshine Boy, was depressed and secretly suicidal.brColumbine shooters mother says saw no signs of his mental distress Sue Klebold Explains Why Shes Coming Forward: Part 1 Columbine shooters mother says .brSue Klebold Explains Why Shes Coming Forward Columbine Shooters Mother Sue Klebold Speaks Out Video FULL INTERVIEW 20 20 Diane Sawyer Sue .