Oxford Community Police say a carbon buildup in the pipe of a gas fireplace caused a carbon monoxide leak in the home early Monday.
Police arrived at the home after provincial police Const. Laurie Hawkins failed to show up for work as scheduled.
Inside, they found the bodies of her 40-year-old husband, Richard, 14-year-old daughter, Cassandra, and 12-year-old son, Jordan.
Oxford Community Police Chief Ron Fraser says Hawkins remains in "severe critical condition" in a Toronto hospital.
Fraser, who fought back tears at a news conference today, said the tragedy has been difficult for many in the local police community.
