Though it's impossible to ever know for certain, the evidence found in Tut's tomb suggests that someone close to him was responsible for his death, and that he might have been killed for political reasons. He was crowned pharoah at a very young age, and belonged to a family of royalty and corruption. He may have died of an illness, but it's more likely that he was killed because someone else was vying for his throne.
I'm doing research on how King Tut died and I don't think he was murdered. Study shows King Tut had malaria which is common in large areas of Africa. Malaria also causes metal confusion and/or suicidal thoughts. Scientists say that King Tut has a chest wound and a broken leg. After finding that out, I figured King Tut commited suicide.
King Tut was not murdered. A recent medical examination of King Tut's remains suggest that he died from an infection caused by a broken leg. There were rumors that he was murdered before this but this evidence has recently solved the mystery that he was not murdered but that he died from natural causes.