☹️☹️
Terribly sad. If it were me I'd be wanting to go too. Why should I live my waning years when my grandbaby is dead because of me, yada yada. I can just imagine the self torture.
In an ideal scenario the entire family would have counselling together and apart, but that would require herculean levels of tolerance and forgiveness.
Changing subject, I personally can actually see how a child can inadvertently be left in a if the routine changes and it's unusual to have the child.
When I had my first baby I was used to being single. Several days after giving birth, I left the buggy with my baby in the clothes shop and walked out. Went into another store before my brain caught up and I went running like a crazy woman back to the first shop. Thankfully no one had even noticed and he was there asleep in the pram.
They drive virtually everywhere in the US it's one the major things I don't like about it. It's not structured for local walking. Driving is walking there.
So you put the baby in the back. Baby falls asleep, is silent. You don't usually have the child, you go into the store or restaurant and forget....