This happened on a freeway I’m familiar with where I’ve hauled horses myself (in summer). First ice or snow of the season.
I’ve seen more details on FB. A SB pickup truck lost control, crossed the median, and became airborne, then slammed into the truck bed of a NB commercial horse hauler. The goose neck separated and the trailer rolled. 3 horses were ejected through the ripped open roof, a 4th horse was let loose after the crash and ran about a mile, but was caught. None seriously injured. Hauler and their dogs OK, but pickup driver killed.
We have a nascent but active interest around here in Technical Large Animal Emergency Rescue with a FB page where they were drawing lessons about what went right and wrong. I Know a pro trainer that had a horse on that load but haven’t talked with her since.
Anyhow very sobering. I live in the metro area which is warmer and flatter for the most part, but if you are up in the ranching and horse country areas you can’t avoid winter mountain driving, the ranch land is mostly river valleys between mountain ranges. A local hay dealer who sold to our barn was killed in a head on mountain pass crash a few years ago bringing in a load of hay from Alberta. The Coquihalla actually has its own TV reality show Highway Thru Hell, about the heavy equipment wreckers serving the area in winter. But mostly the actual mountain pass South of where this latest accident happened.