Sue Klebold, the mother of Columbine shooter Dylan Klebold, has stayed out of the public eye for many years. Now, she’s breaking her silence.

Klebold recently sat down with ABC’s Diane Sawyer and opened up about the events that forever changed her life. Klebold is publishing a memoir, A Mother’s Reckoning: Living in the Aftermath of Tragedy, on February 15th.

“I think we like to believe that our love and our understanding is protective, and that ‘if anything were wrong with my kids, I would know,’ but I didn’t know. And it’s very hard to live with that.

“I felt that I was a good mom… That he would, he could talk to me about anything,” Klebold continued. “Part of the shock of this was that learning that what I believed and how I lived and how I parented was– an invention in my own mind. That it, it was a completely different world that he was living in,” Klebold tells Sawyer.

The interview will air on Friday, February 12th, at 10pm ET on 20/20. But you can check out a portion of it below:

On April 20th, 1999, Sue’s son Dylan, alongside friend Eric Harris, murdered 12 students and one teacher at Columbine High School in Columbine, Colorado. An additional 21 people were injured. After the shooting stopped, both Klebold and Harris turned the guns on themselves.

One of the most shocking events in recent history, Columbine was the first mass school shooting to really shake the nation. Sadly, as we know, many have followed.