New Zealander Grace Adams escaped the infamous Branch Davidian cult in Waco, Texas, but her sister Rebecca was among the 76 people who died there in 1993. Grace says Rebecca's memory drives her work to keep others safe.

Photo: Screengrab / CBS This Morning

Grace and Rebecca left the cult together in 1991, but Rebecca returned and later perished in the fire that engulfed the compound at the end of a 51-day siege.

“To see it end that way, it was awful,” Grace says. “We did not get a chance to say goodbye to her.

“This is what drives me – I don’t want that ever to happen to any families, any person. I’d hate for them to go through what I did and what happened to Rebecca.”

Grace was 29 when she and Rebecca left for Waco with another sister and brother-in-law.

They arrived to find cult leader David Koresh on a bed onstage, yelling and screaming while smashing a long oar on the bed.

“The first night that we arrived it was frightening ... He was very angry.”

To this day, Grace doesn’t know why she stayed.

“There were close to 200 people in the hall that we went into, nobody stepped out of there, no-one bolted.

“There was only one woman brave enough who stood up at the end of all this carry-on and she said she was frightened. All of us just sat there and took it.”

Photo: Screengrab / CBS This Morning

Koresh’s purpose, she says, was to frighten them and make sure they knew who was in charge.

“I think he was very delusional. He had all these grandiose ideas of who he was. He was just out of control.”

Grace has said women and girls older than 12 were expected to have sex with Koresh.

She began hearing voices telling her to go to his room, and eventually thought it may be an answer to her prayer – “maybe this is the way that I get to leave here”.

But when she and another woman went to Koresh's room, he emerged furious that they had taken the initiative, seeing it a challenge to his leadership.

He decided Grace would be isolated in a cabin – a confinement that lasted four months.

There she had a breakdown, she says, sometimes feeling high, other times sleeping all day.

Eventually, Grace informed Koresh that she and Rebecca's visas had expired and immigration officers might investigate. ‘God said you could go now' was his message in reply.

The sisters left together, but Rebecca returned. In 1993, as the siege unfolded, Grace followed it on radio and TV.

She now gives talks and presentations in the United States and New Zealand warning about how people are led into cults and offering fellow former cult members information on recovery.

Among the most vulnerable cult members are people who’ve left home for another state or country and have no friendships or family to sustain them, Grace says.

“Nobody joins a cult. What you’re joining is an idea, what you’re joining is people who have done something for you, and generally, if somebody knew they were joining a cult they would not.”

Photo: AFP

Cult leaders use techniques to frighten and control followers, she says. Koresh could be charming one minute and yelling and screaming the next.

“That personality is changing constantly, and you never know whether what you’re doing is right or wrong because what was right a few minutes ago would be wrong the next minute.”

Cult members are broken down via isolation from friends and family – Grace was discouraged from spending time with her sisters – and deprivation of food and sleep.

When people are “seekers” on a quest to find out who they are and their purpose in life, cults can come in and “short-circuit” that search, she says.

Grace has been back to Waco four times since the siege and will return next week on 19 April – 25 years since the fire in which 76 people died.

“My reasons are, I have a connection to the people, not so much in wanting to continue to believe what they believe, but more [that] I feel their pain and I want them to see I’m well.

“When I left the group I was a very sick young lady. I wanted them to see, this is where I am today, I am well, and you can have a better life than what you have now.”