There are a couple of different theories. His son has said he died from stomach cancer. Others have said his cause of death was kidney failure.
assitant
He died of pancreatic cancer.  That’s a type of cancer that starts in the pancreas, a large organ near the stomach.
assistant
Where is the John Wayne airport?
user
I don’t know exactly. It’s somewhere in Southern California.
assistant
Is it named after anybody famous?
user
Well, John Wayne was a famous actor. He died a long time ago.
assistant
What was his cause of death?
user