Warning: Graphic content ahead, viewer discretion advised.
1. The disappearance of Bobby Dunbar who was "returned" to his family, but turned out to be another child.
3. The Yuba County Five who all had mild mental or psychiatric issues and mysteriously went missing.
5. The Black Dahlia whose murder in 1947 became highly publicized due to the graphic nature of what happened to her.
6. The case of Timmothy Pitzen who disappeared after his mother's body was found with a note saying Timmothy was OK and would never be found.
10. Susy Tomassi an older woman with dementia who disappeared one day and has not been found.
13. The Dyatlov Pass incident where nine people died in the mountains of Russia under mysterious circumstances.
15. The deaths of of Kris Kremers and Lisanne Froon who went on a hike in Panama and never returned.
18. The Oakland County child killer case from the '70s that has had many suspects over the years, but is still an unsolved case.
19. The disappearance of Kyron Horman that sparked the largest criminal investigation in Oregon history.
21. Finally, the widely publicized Madeleine McCann case who went missing from her bed in 2007 while her family was on vacation in Portugal.
Submissions have been edited for length and/or clarity.