From google:
Karen Ann Quinlan was the first modern icon of the right-to-die debate. The 21-year-old Quinlan collapsed after swallowing alcohol and tranquilizers at a party in 1975. Doctors saved her life, but she suffered brain damage and lapsed into a "persistent vegetative state." Her family waged a much-publicized legal battle for the right to remove her life support machinery. They succeeded, but in a final twist Quinlan kept breathing after the respirator was unplugged. She remained in a coma for almost 10 years in a New Jersey nursing home until her 1985 death.
Like Karen Ann Quinlan, Nancy Cruzan became a public figure after entering a "persistent vegetative state." A 1983 auto accident left Cruzan permanently unconscious and without any higher brain function, kept alive only by a feeding tube and steady medical care. Cruzan's family waged a legal battle to have her feeding tube removed; the case went all the way to the U.S. Supreme Court, which ruled that the Cruzans had not provided "clear and convincing evidence" that Nancy Cruzan did not wish to have her life artificially preserved. The Cruzans later presented such evidence to the Missouri courts, which ruled in their favor in late 1990. The Cruzans stopped feeding Nancy in December of 1990, and she died later the same month.