She was 9. I let her out for her early evening pee and forgot that the downstairs neighbours are away, meaning she couldn't do her usual procedure of asking them to let her back in. Then I forgot she was out. I heard her calling from the street (three floors down) but didn't connect the noise with her. I have ME and the brain fog was bad. At 11.30 I finally realised she hadn't had her supper, so I searched the flat, then remembered she was outside and searched for a long time. Finally found her on the pavement. Skull broken, hit by a car. She had probably been trying to get back in for 3 or 4 hours but couldn't because nearly all the people in the building are still away for their Christmas break. So I failed her, and she's dead. The best thing in my life. She's on my lap now. Have hardly let go of her since I found her. My best friend. She wanted me to be a mother to her and I loved doing it. We were like two peas in a pod, doing everything together. On Saturday we went out for the day, on tubes and trains, going to coffee shops and so on. Which was great, because it meant I was carrying/cuddling her for much of the day and she was having an adventure with lots of new things and people to look at. But it was also very tiring, hence the brain fog last night. So if I hadn't overtaxed myself and mismanaged my ME, I'd have got her indoors and she'd be alive, probably for another 10 years. I've never cried so much. Not even when my parents died.