My MIL willed herself to die.
Sadly, that is the literal truth. She owned her home free and clear, and took advantage of our state's Senior homestead property tax break, but she started having TIA episodes and got to the point where she wasn't safe to live alone. Her health was otherwise actually quite good, but she got into falls and all kinds of accidents due to the little blackouts. (At one point she blacked out while eating breakfast and broke her collarbone by falling out of a kitchen chair.) Her doctor told DH she needed to move in with us, but our home is tiny and built like a tower (the bedrooms and bathroom are not on the same floor), and there literally was no safe place to put her, so she had to move into assisted living. It was an affordable place just a few doors down from our home, but she hated it there, and it cost ~$4K per month. By the time she had been there 7 months she had been taken to the ER by ambulance 5 times because of falls in the night, and the bills that Medicare and her Federal retiree insurance did not cover were devouring her savings. We put her home on the market but it wasn't selling fast enough, so we had to subsidize her rent to stretch her funds, and the value of the house was only going to carry her for about 2 yrs. Once she became aware of that situation she largely stopped eating and drinking and started doing things that she knew were dangerous for her, in the obvious hope of having a fatal accident. Her kidneys started to fail and she deliberately did not take her medications for it. She spent the final 6 weeks in in-place hospice, and died in her sleep just under a year after moving out of her home.
She could have moved to a Medicaid AL facility once her funds ran out, but all of those here are set up like dorms, with shared bedrooms and hall bath situations. She was agoraphobic, and the fear of having to live in a truly communal situation like that terrified her. She preferred death over what she saw as a living hell.
Becoming disabled can torpedo even the most careful retirement savings. Many older folks now who saved carefully all their lives (but were never more than the middle of the middle class) rely on a plan that was based on living mortgage-free in their own homes. When that no longer becomes possible and they need to pay rent on a place in a staffed facility, the whole foundation crumbles for most of them.