Tensions reached a head when trader John Oldham was killed after trying to cheat the participants; in retribution, Massachusetts began raids without telling Connecticut, leaving Connecticut garrisons to be slaughtered by the retaliations, until finally John Mason and John Underhill killed five hundred Natives at Mystic River and sold Sassacut into slavery, destroying the nation entirely.  
This conflict was precipitated by the death of Woopigwooit, which caused the separation of the Mohegans.  Tensions reached a head when trader John Oldham was killed after trying to cheat the participants; in retribution, Massachusetts began raids without telling Connecticut, leaving Connecticut garrisons to be slaughtered by the retaliations, until finally John Mason and John Underhill killed five hundred Natives at Mystic River and sold Sassacut into slavery, destroying the nation entirely.  FTP, identify this 1637 conflict between natives and colonists in southwestern New England.
This conflict was precipitated by the death of Woopigwooit, which caused the separation of the Mohegans.  
Pequot War