Why do the protagonists always die in Hemingway's novels?

Question

Why do the protagonists always die in Hemingway's novels?

Answer 1

They don't always die, but in many works of literature the tragic heroes die.

Answer 2

Hemingway, like  was a soldier in WW2 and many critcs attribute his world view (as well as many of his contemporaries) to his experiences in the war.

American writers after WW2 tended to write darker stories.

Answer 3

In "The Sun Also Rises" (perhaps one of his most notable novels), nobody dies.

Answer 4

Hemingway struggled with what I believe was a bipolar condition, a mental imbalance, throughout his adult life. He was often depressed, ultimately to the point of successful suicide.

I think Hemingway simply had his protagonists reflect his own thoughts, sometimes to the death of them. I think Hemingway was bipolar because of his life style, his moodiness and the 'extremes' he lived with all the time, often in life and death situations he gravitated toward, such as war.