On in members of died in what has been called the largest mass suicide in modern history.

November 18, 1978 in Jonestown, Guyana members of the cult Peoples Temple

Explanation:

The leader or pastor Jim Jones of the cult Peoples Temple led 900 of its members to ingest poison. The cult was first established in Indiana back in the 1950s, then moved to California in the 1960s. Finally in the 1970s he moved his Church and follower to Guyana, with the intention of starting an Utopian community. Jones had been chased by bad reports against his followers. That's why on November 18, a US Representative called Leo Ryan went to Jonestown to investigate further. However, he was murdered along with four people that went with him. That same day, Pastor Jones and his followers ingested a poison-laced punch.

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