Some of the more than 900 who died at Jonestown November 1978. [Dave Hume Kennerly/Getty Images]What seemed like a good thing for people on the margins when it started out turned into one of the most horrific tragedies of the late 20th century, thanks to a narcissistic megalomaniac who had just enough charisma to convince politicians he was a godsend and to leave him alone, get a thousand people to follow him into the jungle and ultimately get many of them to kill their children then die because he convinced them it was the best thing for them.