South Simcoe Police are looking for more witnesses to Monday’s fatal crash at Sideroad 20 and Line 6 in Innisfil.
Three vehicles were involved, including one that flipped onto its roof.
That collision killed a 49 year old Toronto woman at the scene and sent 5 people to hospital.
On Tuesday another one of the victims succumbed to her injuries while in a Toronto Trauma Centre.
Alcohol was not a factor and the investigation continues.