So a tree that is on our property right on the property line fell over into our neighbors yard. We really don't talk to them at all. Long story, but they seem to be friends with our other neighbors across the street (the mom of two boys who get arrested all the time, including heroin) so we've stayed away from these neighbors as well.
It's not a huge tree and can easily be cut with a small chain saw.
I started researching and was surprised to realize it's really not our issue. You are responsible for anything that falls into your yard, even if it's on your home, etc. (Which this is not) They will have to pay for the clean up of the tree.
What worries me about knowing this is that some other neighbors behind us have HUGE trees in their back yard that tower over our house. Scary if they ever get sick or die and they don't remove them.
Have you ever had this happen to you before?