How to cope with death

I overheard this conversation between Anna (4) and Amaia (2) yesterday. Amaia was playing with an old mobile phone:
'Hello, Pumpa? It's Amaia'
'You can't phone Pumpa any more Amaia, he died'
'I can can talk to Pumpa if I like, he's still my best friend'
Sometimes I think the smallest children come out with the most profound words.