A Tree, Car and a Sunny day

Was driving down one of our tree filled neighborhoods last weekend. Suddenly, whoosh I heard something fall on my car and braked and closed my eyes. Immediate assumption was I have knocked something. Heard people screaming in the road looked up and huge branch of a tree has fallen on the car. What are the likelihoods of a big branch of tree falling on a sunny day? I just noticed that the side mirror was broken and hanging. All these people came running and took the branches. Was too scared to get out and check the damages just kept driving (idiotic I know).
Anyways drive quite a bit and get off to look at the damages. I get a mixed feeling of desperation where I am crying and wishing the blooming tree had fallen on me instead. Since I have been in a fairly depressive mood I think just broke down. This is the first sort of accident with the car and that too with a tree dropping its branches out of the blue. Insurance is apparently covered for this sort of thing now I am going to be without a car for a good ten days. Tired of answering people who keep pointing at the dents and asking how did you do that? (feel like answering no I just drove up a tree I mean how would the hood get dented and the sides unless I just did that!)