A similar accident occurred in Southwestern Ontario (just east of Detroit/Windsor border) a couple of years ago and it was a horrific mess. Cars drove into sudden, thick fog and as they slowed down realizing they couldn't see tractor trailers started running into them at 60mph from behind. Many dead. Pictures taken after the fog cleared looked like a scene from the attack on the convoy of Iraqis fleeing Kuwait in Gulf War I. Here's hoping for as few fatalities as possible. These accidents tend to be truly horrible.
Yes, these are always horrific accidents. When I heard the first reports this morning, it didn't mention the fog, just that the interstate had been shut down due to a southbound accident, with the northbound lane closing due to rubbernecking accidents.
We had a similar accident in Green Bay about 10 years ago up on the Tower Drive bridge which had a few fatalities and a major pile-up. This one is being described as the worst of its' kind ever in Wisconsin.