Neighbor suing me over trees on my property

Greetings,

Quick notes:
I live in CA
Neighbors for over 23 years
Never a problem
Suing me 3 separate times in a few week span

First suit: A branch from one of my trees he claims landed on his car. Fell overnight. Woke up, went over, asked if his vehicle had any damage, he said no. Removed branch, trimmed tree. Few weeks later, get served. Am I responsible for the damage he now claims? He never came over to talk it over. Tree was and is still healthy. Does 'Act of God' apply?

Second suit? Same as above basically. Said a branch from one of my trees landed on his in-laws car. Paid for the damages now wants me to reimburse him. What the...?

Third: Says roots from my trees have caused cracks in his driveway. These tress are old, were there when we moved in and I'm almost positive that they date back before his driveway was put. Now wants over $1000 to repair driveway. Again, am I responsible for the 'damages'?

Any and all help is much appreciated. All of this has blindsided me and I'm at a loss.

Regards

[AFFA]

I wish to inform you that in your first problem you may not be made liable because there was no damage to the car. The burden will be on your neighbor to show that there was damage and as to why he has not spoken truth. In second situation you may be liable. In this only the amount of actual damage may be claimed. In third situation you may be made liable as the damage was done by your tree roots.

AFF