Fortunately, no one is held liable for acts of nature. If a tree fell on your house whether from your yard or some other yard due to a natural occurrence you should be covered under you own homeowners policy for the damage.
I saw on one of the court shows where that exact thing happened. A tree fell into a neighbor's yard and damaged their fence. The neighbor tried to sue the guy who's tree had fallen. However, the judge said that it was not the guy's fault that mother nature caused the tree to fall. However, if the neighbor had given multiple written notices in advance asking the neighbor to please have the tree chopped down, the she would have had evidence that there was an on-going problem and the guy would have been responsible for damages to her fence.