Legal Question in Civil Litigation in Massachusetts

Re: Neighbors tree

If it is a known danger that is easily recognizable they would be responsible for not taking action. If it is purely an act of God where trees fall they are not. It appears that this is a known danger. They should be warned and you should check with the town tree warden.

Re: Neighbors tree

If the tree is on their property, they would be liable should the tree fall and do damage to your property or persons.

You might want to send them a letter by certified and regular mail (perhaps copying your town authorities as well) putting them on notice that the tree represents a hazard, and should be taken care of immediately.

If they refuse, you will at least be on solid ground in the event that any damage should occur.