Why do people die?

The Gemara in Bava Metzia 107b discuses this very question and comes to some startling conclusions.

Rav states that 99 out of 100 peoople die because of עין הרע.
Shmuel says it's not because of עין הרע but because of wind. Rashi explains, all sicknesses and death come because of the wind. Different winds affect different people. The Gemara asks what about people who are executed? Shmuel answers if the not for teh wind that gets into the wound we could heal them with some ind of medicine.
R' Chanina says people die due to cold and/or heat (this is not the same as wind) as R' Chanina says that everything is in the hands of heaven except for cold and heat. This statement of R' Chanina is fascinating in and out of itself. He clearly and unequivocally says that certain things are not from heaven which contradicts the current Charedi hashkafa that even a leaf doesn't fall without it being decreed from heaven.

What are we to make of these statements about the causes of death? We know today why people die and it is not for the reasons stated above. One thing we see clearly is that the Chachamim had no real mesora about these issues, they had no idea why people die and therefore they each came up with their own theory.