Snow and black ice caused a number of serious collisions during Tuesday morning's commute including a fatal accident on Highway 7 near Carleton Place.
Lanark OPP say the collision involved two vehicles near Ramsey Concession in Mississippi Mills.
Police say 28-year-old Nader Kawash of Carleton Place was killed in the crash.
An Orgne Air Ambulance was on scene to transport the other driver to hospital with injuries.
In Ottawa, three people were injured after a vehicle left Highway 417 eastbound at Moodie Drive and plummeted down into a 40- foot ditch.
Ottawa Fire had to use extrication tools and stoke baskets in the rescue operation.
The 48-year-old driver suffered back and lower leg injuries.
Two other passengers suffered non-life threatening injuries.
A fourth passenger was not injured.
The cold weather and snowfall caused at least 40 collisions on city roads by noon according to Ottawa Police.
There are about 50 crashes on a typical day.
Police are urging drivers to slow down because of cold weather and black ice conditions.
