I was 6 and it was an elderly member of our community that I wasn’t close to. My parents thought it was wise to expose me to the situation in a kind of neutral way, before I had to experience the loss of dear loved ones. They answered all my curiosities in a factual, non-emotionally charged way and I remember it to this day. We did the same thing with our own DS at around the same age. Sadly, he was only 4 when his beloved grandpa died and was just too young to participate then.