>>28688613
Looks like just too fast for the conditions to me.
What most never think about, and that includes truck drivers, is that the tire sizes and inflation are specced for a loaded truck. In the US the common interstate load is 80,000 lbs (that being the federal minimum maximum that most states adopted as their maximum). So 40 tons. Such a truck unloaded will be in the 14 ton range (@10 tons tractor and 4 tons basic-bitch trailer. So now you've got all this tire area but it's lightly loaded so the ground pressure is low, probably lower than a car's, which make it very easy to lose grip in poor weather condition. Further, Euros use super singles and those are known to be terrible with grip in adverse conditions which is one reason, among many, that independents refuse to use them.
Factor in too that, as previously noted, everything has been driving out experienced drivers in favor of idiots that work cheap and you get a guy that's pushing it with a "light" truck in the rain and somebody (probably) dies.