Watched another trailer come loose!!

[Whatswrong]

I am guessing nothing failed other than the human that hooked it up.

Looks like an empty little landscape trailer that may weight 800lbs? Hard to believe there was a mechanical failure anywhere.

Wrong size ball? Forgot to latch? Most likely two IMO

I agree with every comment ,plus a definite was no safety chain .
Lots of people don't like them or believe in them ,think they don't want what they are pulling dangling along on chains.
I know of a service man that used to come to our office to work on the copiers etc. A gentleman towing his boat without safety chains lost it and it hit the van killing that man and doing a lot of damage to the other service man in the car.