Ontario's Special Investigations Unit is investigating a fatal collision between an OPP officer and another vehicle southeast of Ottawa on Sunday.
Stormont, Dundas and Glengarry OPP said an officer was responding to a call around 12:30 a.m. Sunday in a marked vehicle with the lights on.
Another vehicle collided with the OPP vehicle on County Road 31 in Morrisburg, between Cornwall and Brockville, for what police said are unknown reasons.
Both vehicles ended up in the ditch, and the 52-year-old female driver of the civilian vehicle was pronounced dead at the scene.
Police said she was from Williamsburg, about 70 kilometres southeast of downtown Ottawa.
Three of her passengers were taken to hospital in Winchester – two in serious condition who were later taken to hospital in Ottawa, and one who was treated and released in Winchester.
The police officer was taken to hospital in Winchester where they were treated for minor injuries and released, according to police.
County Road 31 is closed south of Deeks Road for the investigation.
