How to explain death to a three year old

[PinguFanatic]

So my mum died seven years ago. My DC1 who is three asked me where my mum was the other day (totally out of the blue), and well, after a long and badly worded conversation from me he now keeps asking me "where's your dead mummy" is and "can we go and find your dead mummy"

I'm wondering if anyone can recommend any good books I can read to him, or any way I can try and explain to him that "no, we can't go and find her".

Could you visit her grave? I seem to remember my children exploring the concept of death around this age. My only advice would be to keep it simple.

we are not religious so couldn't go down the heaven etc route

I told ds that sometimes bodies stop working and the person dies. But the person always lives on in the heart of the people who loved them and the only way we have of staying in touch with them is for those people to relate memories of the person

he didn't quite get it at first and we didn't discuss young people dying (he thinks only really old people die)

he is just getting an idea of time - so we were talking about something that happened 100's of years ago and he asked if the people from then were dead now

I was in a very similar position with my DS (3 years) the other week. He was asking why I didn't have a daddy. I explained that my dad had died a long time ago. DS made me sob when he told me that when he got big he would help me find my dead daddy and bring him home. I found it really difficult to explain it to him - especially because I kept crying.
I will have to think of something soon because my sister's much loved dog has been given a couple of months at the most and DS will be distraught when he goes.