She wasn't permanently lost, but my aunt joined the Children of God in the 70s. She was down in Texas doing student teaching and one day her roommate called my grandparents to say she hadn't seen her in a couple days and was pretty sure some people took her to Mexico.
My grandparents immediately drove down to Mexico, hired a cult deprogrammer, and rented a house near the cult compound. They basically blew as much money as they could afford, but never saw her before they had to give up and go back home.
A little while later, my aunt called home to tell her parents she was getting married. They told her to wait until spring break and they would come down for the wedding, but she said she couldn't. A few months after that, she brought her new husband to the US to meet the family.
They're still married today and I basically just learned about the whole thing like 6 months ago.