Durham Regional Police say the truck was moving across the ice near Thorah Island, when it came to a break in the ice.
The driver lost control and the vehicle flipped over at 4:35 p.m.
Five people were inside the truck at the time of the incident, some of whom were thrown out of the vehicle.
Police say a 32-year-old woman is dead as a result.
Two men were taken to Toronto’s Sunnybrook Health Sciences Centre after the crash — one went directly via air ambulance, while the other went to an Orillia, Ont., hospital first before being airlifted to Toronto.
A third man suffered non-life threatening injuries and was taken to a hospital in Uxbridge, Ont., while a fourth man with minor injuries was treated at an Orillia hospital.
The crash remains under investigation.