Yep, seen that earlier. The trailer detached from the towing vehicle and hit the tree. That's why I strongly believe the trailers should have registration plates like cars and be subject to MOT requirements - with properly serviced trailer this wouldn't be possible; shouldn't detach in the first place and if detached - an emergency brake should stop it.

I learned this stuff the hard way myself a few years ago when I purchased a horse trailer, nowhere else on the continent that thing would be allowed to be used on the road. Before it was roadworthy I had to replace brakes, tyres, emergency brake device and the floor. Unfortunately here in UK there is no obligation to keep them in a good shape, that's why there are so many accidents involving trailers (in horsey press there's one almost every month...)