On December 28, 1992, 9 year old Katie Beers was abducted in Bay Shore, New York, just two days before her 10th birthday. Her disappearance launched a massive investigation that revealed a shocking history of abuse and neglect that started years before her disappearance.

Sources:
Killer Carnies - Season 1, Episode 3: Dungeon of Doom from Discovery+
The Horrific Kidnapping Of Katie Beers And Her 17 Days In An Underground Bunker from All That's Interesting
Katie Beers: Abduction, Abuse Led to Present Happiness from ABC News
Katie Beers: Kidnapping allowed me to escape abuse from CBS News

The Boy in the Box (AKA Joseph Augustus Zarelli) Update from the New York Times