My Dad owns property that has very tall trees on the property line (50-70 feet tall), abutting another property behind him that has commercial trucks parked about 10 - 20 feet from property line. He tells me the condition of the trees are not great and is worried that they'll fall hitting the trucks. He wants to know if he'd be liable if that happens. I told him that if a tree that is located on his property falls and strikes the property owned by a neighbor or the neighbor's invitee, etc., and the trees are determined to be in poor condition at the time, he is definitely liable. He's old and stubborn and doesn't want to spend the money to have the trees doctored or cut. I told him an ounce of prevention is worth a pound of cure. I also advised him NOT to write to these people as he wants to and warn them about the trees, as it's an admission of guilt (of sorts) if anything does happen. Anyone?