Heaven's Prisoners

How can a religious group convince, coerce or even compel its members to take their own lives? By that, I'm questioning capability, not morality. There must be some sinister or even supernatural machinations involved. On March 26, 1997, 39 followers of the cult Heaven's Gate died in a mass suicide in Rancho Santa Fe, California - believing that they were 'exiting their human vessels' so that their souls could go on an adventure aboard a spaceship trailing comet Hale-Bopp(!). And they were all wearing Nike sneakers at the time of their deaths. By comparison, Scientology now looks like Sunday school.