Bad weather overnight could be the reason for two deadly accidents on Ontario roads.

A 20-year-old woman died just before the dinner hour Saturday night when a car she was riding in collided with a pickup truck in Caledon.

The car, going southbound on Highway 10, spun out and was struck by the northbound truck on the passenger's side, where the woman was sitting.

Ontario Provincial Police and firefighters also rushed to an accident scene in Barrie at around 2 a.m. Sunday.

A small car lost control and slid sideways into an oncoming bread truck.

A passenger sitting in the front seat died at the scene. The driver and a back-seat passenger were sent to Royal Victoria Hospital with life-threatening injuries.

Police are still investigating whether or not the weather played a role in the crashes.