Oh death!

Why oh why do these accidents happen. This car on its roof in the ditch is on a stretch of straight road with no junctions within a couple of hundred yards and no evidence of any skid marks on the road. I do hope no one was seriously hurt.
How did it happen.....was it speed or alcohol?
Strangely a week or two ago there was another one that had left the road and gone down the bank but that is a couple of miles further on and possibly a corner was taken too quickly and the driver lost control.
It is such a shame that the drivers do not take more care!