The cause of a fatal two vehicle collision in northwestern Ontario is under investigation. An elderly couple died when their westbound Chrysler struck an eastbound transport about 15 kilometres east of Fort Frances yesterday afternoon on Highway 11. The driver of the tractor-trailer unit wasn't injured. The driver of the car has been identified as 82-year-old David Chambers and the passenger has been identified as 75-year-old Louise Chambers, both of Fort Frances.