if a tree fall down

This tree is on the padestrain/sidewalk across the road in front of my house, or outside my neighbor's house. 

It is belong to city so I sent an email asking the check the status and they ask me to pay for

As I reported the dangerous to the owner=city, once the tree fall down and damaged my house, who would be responsible for it, me, my naighbor or city? any law on this? I'm in Califronia.