Oprah Radio host Gayle King talks with psychologist Dr. Susan Lipkins about preventing school shootings.

Oprah Radio host Gayle King talks to the father and brother of Rachel Scott, who was killed in the 1999 Columbine High School shooting.

After the tragic death of a child, a Wyoming man begins serving his sentence with this letter.

On April 20, 1999, a deadly rampage at Columbine High School in Littleton, Colorado, took the lives of 12 students and one teacher. Over the years, Oprah spoke to many of the survivors, including Craig Scott, the brother of the shooters' first victim, Rachel Scott. Watch as Craig returns to the scene and shares the biggest challenge he faced after the massacre.

Lisa and Kristy are sisters who feel their mother is self-absorbed and uninvolved in their lives. But their mom, Donna, disagrees and says she's enjoying life without the responsibility of raising children. Now, with the help of Iyanla Vanzant, they've come together to have a hard conversation. Watch as Lisa and Donna finally tell each other the truth about how they're feeling.