Are you thinking about the Jim Jones mass suicide in Jonestown, Guyana?
>>>On November 18, 1978, Peoples Temple founder
Jim Jones leads hundreds of his followers in a mass murder-suicide at their agricultural commune in a remote part of the South American nation of Guyana. Many of Jones’ followers willingly ingested a poison-laced punch while others were forced to do so at gunpoint. The final death toll at
Jonestown that day was 909; a third of those who perished were children.<<<
https://www.history.com/this-day-in-history/mass-suicide-at-jonestown
Just curious, I don't remember a mass suicide in Mexico, but it's certainly possible. There have been a few.
I think this is the spaceship cult:
>>>Following an anonymous tip, police enter a mansion in Rancho Santa Fe, an exclusive suburb of San Diego, California, and
discover 39 victims of a mass suicide. . . . It was later revealed that the men and women were members of the
“Heaven’s Gate” religious cult, whose leaders preached that suicide would allow them to leave their bodily “containers” and enter an alien spacecraft hidden behind the Hale-Bopp comet.<<<
https://www.history.com/this-day-in-history/heavens-gate-cult-members-found-dead
