Ontario Provincial Police are investigating a fatal collision on Highway 17 between White River and Marathon.
Marathon OPP say they responded to the single vehicle collision about 70 kilometres east of the town - near Green Lakes - around 1 o'clock this morning, finding an eastbound Honda Civic had lost control after hitting the eastbound shoulder on a corner - the vehicle entered the eastbound ditch, flipping and landing on its roof.
All four people in the vehicle had to be extracted by emergency services, with a 35-year-old female passenger pronounced dead at the scene while the driver - a 31-year-old from Guelph - was taken to Marathon's hospital before being transported to the Thunder Bay Regional Health Sciences Centre for treatment of major injuries, and two other passengers were taken to Wawa's Lady Dunn Health Centre for treatment of major injuries.
Their names are not being released, pending notification of next of kin.
The collision's closed the eastbound lane of Highway 17 for several hours, while the westbound lane is open to intermittent traffic, though drivers are warned to expect delays, use caution, and move slowly through that area.