Unfortunately this story simply goes to reinforce the mentality that it was not driver error - it was the fog's fault.
Let's be clear fog in itself does not cause crashes - its soft and fluffy how could it do any damage! The cause of the crash was of course motorists driving inappropriately for their skills, the conditions or both.
A skilled motorist would notice the conditions before they had started their journey and adjusted their speed accordingly. Ideally they would have noticed the fog warnings on the weather the night before and were therefore ready to leave the house earlier than usual recognising their journey would take a little longer.
Be careful out there.