Dorothy Sterling, 80, and Dorothy Wu, 85, were probably the first to die.
Their nurse, Roger Dean, set fire to an empty bed in their Quakers Hill nursing home room and then left them to perish, knowing they were incapable of moving unaided.
Then he destroyed evidence that he had stolen prescription drugs from the home and told a chaplain, "Things like this make me lose my faith in God".
On the first day of his Supreme Court trial on Monday, Dean, 37, pleaded guilty to the murders of 11 elderly residents who died as a result of the fires he lit at the home on November 18, 2011.
He also admitted to causing grievous bodily harm to a further eight residents who were injured in the blaze, described by paramedics and firefighters as one of the worst scenes they had ever come across.