I have to say good - while sorry for those who lost family members - they had held the fireworks there for a number of years without incident and in the end its up to the drivers if they see a bank of fog to slow down

Exactly drivers should be driving at a speed that is appropriate for the conditions. If there was smoke fog or anything that impairs that visibility they should slow down and if it was as thick as they claimed then fog lamps should have been used as well.