US 41/45 closed just north of Milwaukee

Here's some pics. Dump truck shmucks SUV, several cars involved. Dry roads, sunny skies.
http://www.wisn.com/news/images-highway-4145-crash/31613086

 

From the comment section (from witness): "We literally were right behind the first car that crashed (the black SUV). My wife barely swerved and avoided it and I called 911. Some cars behind us must have hit that vehicle."

Hard to say exactly what actions happened first.
But like "semi" retired said... "Dry roads, sunny skies".
No excuse.

 

+ it's 3 lanes in each direction with a grassy median and shoulders on each side. And it's fairly flat with only a slight curve.

Yet for some reason there are a lot of bad accidents on this stretch.

 

Yeah, I noticed he was in the farthest left lane (of the 3 lanes), which doesn't look good for him, but it's unknown if he ended up there to avoid another 4-wheeler.
There was a couple of smashed 4-wheelers behind him too.
It's also right by an exit ramp, so no telling if 'someone' made a 'last minute' decision, trying to exit.