Well, 'Unbreakable' is purely fictional. It's crafted from the imagination of those involved in its making. There are no real-life events or people behind it.
The film 'Unbreakable' is based on a concept that has elements of truth in a broad way. It's not a direct retelling of a specific true story but rather plays with the idea that there could be people in the world with unrecognized, almost superhuman capabilities. For example, there are real people who have shown amazing strength in times of crisis or incredible endurance. The movie takes this idea and builds a fictional story around it.
Definitely not. 'Unbreakable' is purely a work of fiction. It was written and directed with an imaginative plot and characters that are not based on real events or people.