On May 6, 2013, Berry called 911 from a neighbor's house, saying, "I've been kidnapped and been missing for 10 years. I'm here. I'm free now!"
Berry and DeJesus will be recounting their experience with ABC's Robin Roberts -- their 10 years in captivity, the child Berry had with Castro and that fateful day when they fought their way to freedom.
In a preview of that interview, Berry describes the moment her young daughter, Jocelyn, noticed that Castro was away while her bedroom door was unlocked.
"My heart immediately started pounding 'cause I'm like, 'Should I chance it? If I'm gonna do it, I need to do it now,'" Berry said.
She got the attention of some neighbors, who helped her kick down the door to the outside, ABC News reports. Berry ran to call 911, and the police helped DeJesus and Knight escape.
Berry and DeJesus described their years in captivity leading up to that astonishing moment. The three captives were held in Castro's house with the child that Berry had after Castro raped her.
Little Jocelyn had as normal of a life as they could manage, her mother said. They set up a make-shift schoolhouse and would go through the motions of an imaginary trip to school each morning.
"We would pretend to leave our house, all of us in the same room of course," Berry described. "I would tell her, 'OK, we're at a street now, so you gotta stop. Then you look both ways for cars, and then we can go across the street.'"
Berry also described the early days after the abduction, saying she had a tiny black and white television on which she watched her tearful mother and sister address the public and beg for help getting her back.
"That kept me going," she said. "And I said, 'You know what, I'm gonna make it home to you. As long as you fight, I'm gonna fight.'"
Roberts said she was moved to tears by their story. She said she would understand if they were fragile, but when speaking with them she saw only strength.
Berry and DeJesus have also written a book about their journey, entitled, "Hope: A Memoir of Survival in Cleveland." It was released Monday.
Watch the one-hour 20/20 special, Captive: A Journey of Hope and survival, Tuesday, April 28 at 10 p.m. ET | 9 p.m. CT on ABC.