Another site makes a bit more sense: "The Freightliner Sports Coach had crested a hill on hwy 43 about 3 kilometers east of Fox Creek when it came upon a slow moving set of vehicles. The Freightliner swerved towards the slow lane side ditch to avoid a collision with the rear pilot vehicle. When the Freightliner hit the ditch this caused it to roll coming to rest on its roof." I still don't really understand it, though - driving too fast and/or not paying attention? Hard to imagine how awful that would be, though - what the driver has to live with :(