That's known as a terminal illness.
she died from Terminal illness http://en.wikipedia.org/wiki/Miley_Stewart
Terminal illness is a state of illness from which one is not expected to recover. The expectation is that the illness will take the person's life.
Wanting to die is not an uncommon feeling when a person is in pain for a long period of time or has a terminal illness. This is why pain management is so important for terminally ill people.
There's no real way of knowing when you are going to die. It's possible to have some indication when if you are suffering from a terminal illness but even then the allocated time left cannot be 100% accurate.
George Freeman (a really lovely man)died in 1990 after a long battle with a terminal illness.
Most were killed from the explosion, some survived but may have short term or long term radiation illness which can be terminal.
You die
He died due to a long-term illness he had.
she isnt dead shes 82
don mckinnon isnt dead
they will die