A 68-year-old woman suffered life-threatening injuries when her car left a highway and rolled over.

The single-vehicle crash occurred around 3:30 p.m. Tuesday, on Highway 54 near Painter Road, east of Brantford.

Brant County OPP say the car missed a curve in the road and rolled over into the ditch. Speed is considered a possible contributing factor.

An air ambulance took her to a Hamilton hospital for treatment.

Highway 54 was expected to remain closed in the area until late Tuesday night.