I really want to just go put something under the wheels but I’ve never talked to these people.
Update edit: thank you for all the replies. I went over and knocked but no answer. It’s definitely not chocked. If I see them come home I’ll go back over. I’m worried as soon as the weight shifts loading it that it will just go down the hill.
If you were my neighbour I would love it if you notified my of the danger. I’d also say that if they give you a negative response they will move soon so there’s no risk really