Just finished watching the two part Jonestown: Terror in the Jungle on BBC 4 Storyville. https://www.bbc.co.uk/iplayer/episode/m000d27r/storyville-jonestown-terror-in-the-jungle-episode-1
If you aren’t aware of this story https://en.wikipedia.org/wiki/Jonestown
The brief synopsis is religious cult decamps to Guyana led by Jim Jones, their leader. It turns gradually into a nightmare, and leads to a US senator visiting to seeing what is happening. As he leaves he is murdered, and Jones then orders his following to commit suicide. 918, including 304 children die. Some ‘willingly’, but many forced. Its grim viewing. Has some parallels with the Waco documentary that was on Storyville last year.