Such sliding can even occur on surface roads (wet, not even iced) at non-highway speeds.
I’ve done my best to drive defensively when cars are sliding about. Lesson one is lowering speed below the limit.
I’ve had close calls but have avoided such accidents and it is nerveshaking when it happens.
Cars with bad brakes, bad tires, too much speed, following too closely...
Why didn’t authorities down there drop the speed on that roadway and post LEOs to enforce it.
The bad weather wasn’t a surprise. Neither was the fact that you’ve got drivers unfamiliar with how to drive in it, and likely cars not maintained and/or equipped well enough to drive in it safely.