It is indeed a complete shock. My deepest sympathies go out to all those involved in this crash, as well as the brave emergency services who put their lives on the line to help others.
Our roads are incredibly safe but something like this just reinforces how important it is to develop good driving skills. (Even then I doubt the accident would have been avoided, but why were people going so fast when visibility was so poor? Perhaps they did hit a sudden and dense patch of fog or smoke and there was little they could do about it.
It will be of interest to me to see the causes and contributing factors of this crash, if only to learn by it myself.