My little boy died from SIDS before my other babies were born. I had him cremated and he is in the baby garden. DS had been going there more or less since birth to visit, as did DD1 when she came along (as we all do now too).
I had people telling me it was wrong, and that it was morbid, and that I shouldn't tell them about their brother and do a 'big reveal' when they were older, but I never had to because he was just always part of my family anyway.
I went into hospital to have DD2, the kids were excited to have a new sister, we had bought clothes, a cot, a pram all the usual baby stuff. 2 weeks after I had my very ill little girl I had to tell my children we were turning off her life support, they didn't understand because it sounded to them like we had a choice. They had to have me tell them their sister had gone up to be with their brother and feel like she didn't love them enough to stay here. They had to witness me packing all her things away and not understanding why, they went with us to put her ashes with her brothers.
I've had, and still get regular questions about their brother and sister that breaks my heart because they shouldn't have to deal with any of this. They draw pictures of us as a family playing in the park or whatever and their brother and sister in the clouds watching, they always include them in school work and wherever else they can. Its bloody heartbreaking they have had to deal with such pain and I can't fix it for them.
Explaining that children sometimes die and dealing with a few questions about it would be a bloody relief compared to the daily torture that is trying not to cry in front of my children when they ask, and explain to them what happened and why over and over again.
To those who would be horrified and don't think its the right place etc you should think yourselves very very lucky that you have that choice. Far too many of us don't and are thrown into it well before we are ready to be talking to our children about death.