My friend and former brother-in-law passed in November, my niece along with him. It was sheer luck my other niece and nephew weren't in the car at the time. Ordinarily they would have been.
Anger was the first thing I felt too. In my case it's a bit different since I do believe it was preventable and in many ways his fault, and not only was the child that died involved, but he had two other children who had nowhere to go but to me after the accident. But I think anger is a natural reaction to any kind of death of someone close. You're in too much shock to grieve and anger is easier to cope with until you're in a more stable place mentally to deal with the sadness.
The five stages of grief are a theoretical model of how grief works in most people. There are some criticisms that are well-founded of it, but the basic ideas behind it are solid. Some people have them in different order, or skip some, but overall there's a predictable progress of what people go through mentally during a loss or a trauma:
- Anger (with the deceased or with other people/forces; a way to insulate oneself from the sadness until later)
- Depression (classic grief, sadness, lack of motivation or direction)
You'll probably experience a lot of different emotions, in the months and even years to come. But you'll get through it.
Had a lot of different losses of different people and under different circumstances.