We've had to deal with a similar situation, and will do again in the future.
DH's uncle lived alone and became ill in his 80's. He had an older brother (late 80's, living miles away, with only the odd phonecall contact) and DH - we live 200 miles away.
Eventually, he collapsed at home and was only found when DH couldn't get any reply on the phone, so called the police who broke in and an ambulance carted him off to hospital, where he died 2 weeks later.
After he died, DH spent weeks having to deal with death certificates, notifying the bank, council, energy suppliers etc, sorting out probate, the funeral etc. His uncle hadn't made any arrangements at all for what would happen when he died - no funeral plan, no will, and he didn't have enough in savings even to cover the funeral. We had to foot the bill, plus the bill from the police for securing the property after they'd broken in, the insurance excesses etc.
DH had always been much closer to his uncle than his.uncle's brother was, so it was only.natural that DH felt.responsible for sorting the affairs out, clearing his property out etc, but none of this had been formalised in a will and the estate was eventually divided up, according to the rules of dying intestate, meaning the other uncle got half of everything.
My own mum lives alone and is 84. She has a 4 bed detached house full of junk that should have been sorted when she moved into the house a few years ago, but wasn't. I am one of 4 siblings - we all live in different parts of the country, all have different family responsibilities of our own etc. I know she's written a will and taken advice so as to avoid as much inheritance tax liability as possible, but she has also said on several occasions that she doesn't care what the fall out will be when she does because she won't be around to see it - so, for example, on occasion she's gifted money to 3 of us but not the 4th, and told the 3 of us that it's down to us to make sure that the 4 th sibling gets that money after she's died.
No-one wants to have to think about dying but I do think it's selfish not to have some kind of arrangements in order as you get older, knowing that other people will have to deal with it all after you've gone.