Elizabeth Smart, who was abducted from her Utah home nearly 10 years ago, wiped away tears while speaking at a Salt Lake City Rotary Club about the night Brian Mitchell kidnapped and raped her.
Her unflinching account, reported by ABC News affiliate KTVX on Tuesday, details the harrowing ordeal.
Smart has recounted her ordeal in a book and in the courtroom, but rarely has she spoken of it in public.
She is speaking out as the Elizabeth Smart Foundation is trying to spread its group radKIDS in schools throughout the country.
RadKIDS, an organization that empowers children to protect themselves from danger, is based in South Dennis, Mass.
"I don't want another child to feel like I felt," Smart said. "I don't want another child to feel worthless."
Smart, who is a commentator for ABC News on missing person and child abduction cases, relived the nightmare on Tuesday.
"I kept begging him to let me go -- and he wouldn't listen to me," she said. "All I could do was scream 'No.' He said, if you ever scream like that again, I will kill you."
Smart had been kidnapped from her bedroom in 2002 at knifepoint while her 9-year-old sister, Mary Katherine, watched from her own bed. Her four siblings and parents, Ed and Lois Smart, slept nearby.
Smart told the audience she was afraid he was going to follow through on that promise, so she made one request.
"I turned to him and said to him if you are going to kill me please do it here so my family can find my remains. And he said, 'That's not what I am going to do yet,'" she said.
Instead, Mitchell –- a homeless Salt Lake City street preacher -- performed a quick wedding ceremony. Smart was 14 years old.
"He went straight from marrying me to raping me. And after that moment I couldn't feel more worthless and more degraded. It was the worse feeling I could have ever felt."
Smart, who is now a 24-year-old senior at Brigham Young University, said on the first night of her abduction, she woke up to find her a cable around her leg.
"Everything that was sharp or could cut through metal was out of reach. So, I thought this is the end. It looks like I am stuck here," she told the Rotary Club.
Mitchell and his companion, Wanda Barzee, held Smart captive for nine months.
"I think my body just shut down because I couldn't handle what I was feeling and everything that was happening," she said.
Smart was eventually found alive March 12, 2003, by passers-by in a Salt Lake City suburb less than 18 miles from her home.
And this May, with the help of Smart's testimony, Mitchell was sentenced to life in prison.
ABC News reporter Katie Kindelan contributed to this report.