A depressing topic:
Disease.
Any significant change in the environment. (climate, pollution, etc)
Overpopulation.
Many things could cause humanity to die out. Isaac Asimov wrote an interesting book called "A choice of catastrophes" on this very subject.
Possibly a bad alternator. The Alternator charges the battery when the vehicle is running. If the battery is not being charged this could cause the vehicle not to start.
Of course. How would they help someone who could possibly be dying?
It could be the cause.
Penguins are dying due to climate change of course. How could humans do such a thing? If it was me, I would not pollute the sea. I am feeling very sad for the penguins.
Alcohol withdrawal does not cause heart attacks, although you might possibly feel that you are dying from a lack of alcohol.
Possibly, but not without knowing the specifics surrounding why they are dying.
Climate change is the major cause of dying forests in Germany.
they are being overhunted by humans.
Clogged fuel filter, dying fuel pump, or possibly fuel pressure regulator.
humans
Humans need to keep healthy if they are to avoid the risk of dying prematurely.
man i had a dream about julius caesar dying cause i did it.