They will do it if they believe in God (Allah). Suicidal Americans are not that hard to find.
1978: Mass suicide leaves 900 dead
The bodies of 914 people, including 276 children, have been found in Guyana in South America. Most of the dead - members of the People's Temple Christian Church - had consumed a soft drink laced with cyanide and sedatives.
Last year Jim Jones and most of the 1,000 members of the People's Temple moved to Guyana from San Francisco after an investigation began into the church for tax evasion.
Of course suicide is common, the whole idea of taking someone with is is not.