Who is responsible???

[Ricardo P.]

My NEIGHBOR HAS a nice size tree that has over grown HIS back yard. The tree limbs are over grown and are hanging over my side of the property. I don’t mind cleaning the fallen debris from it since it provides shade in/onto my property. But My ONLY concern is the following. There is a nice size tree branch hanging on my electricity wire that comes down from the City Pole into my fuse/relay/electricity box. 

1.Who is responsible for the upkeep of the tree?

2. Who is responsible for damage caused by the tree? 

3. Can I cut the branches on my side of the property? 

I heard that if I cut the branches over hanging my side of the property and I damage the tree I can get sued?? 

Anyone have any advice?  

Again, tree is in neighbors yard. 

Location is in California.