1A

What do you think the boy witnessed in July 1980 in the prologue? Why wouldn’t he say a word for six months?

I'm guessing the boy discovered that someone had killed herself with car exhaust fumes. I got the feeling it might be his mother.
I think the six months of silence may have been due to the shock and his very young age.

I also thought it was a suicide, but didn’t necessarily think who it was.

I thought someone had been killed.

It appeared to be someone that had killed herself by running the car in a closed garage. I assumed it was is mother

I would agree that it was his mother's suicide in a closed garage.

I also agree that it was a suicide and was more than likely the mother.