The Shafia Family murders took place on June 30, 2009 in Kingston, Ontario. Shafia sisters Zainab, 19, Sahar, 17, and Geeti, 13, along with Rona Amir Mohammed, 50, were found dead inside a car that was discovered underwater in front of the northernmost Kingston Mills lock of the Rideau Canal on the same day. Zainab, Sahar, and Geeti were daughters of Mohammad Shafia, 58 and his wife Tooba Mohammad Yahya, 41. The couple also had a son Hamed, 20. Rona, who was herself infertile, was the first wife of Mohammad Shafia in their polygamous household.
http://en.wikipedia.org/wiki/Shafia_family_murders