Upon his original discovery, it was assumed that man was a recent hiker that lost his way and became trapped in a snow storm. As the body was carbon dated, it was quickly discovered that this body was a lot older than originally thought.
As found in the website highlighted, in 2001, the contents of the Iceman's stomach provided key evidence as to the time of his death and also the whereabouts further in 2002. As numerous grains are found, it is possible to determine that the time of death would have approximately been during the late spring or early spring. The discovery of the contents of the stomach was a major breakthrough in this investigation as originally, some argued that a possible cause of death may have been starvation. With the finds of a full stomach, this hypothesis was completely ruled out.
In 2006, CAT-scan results revealed that the arrow that was shot into the Iceman's back, punctured a major artery. Such an injury would have resulted in a major amount of blood loss. This piece of evidence became undoubtably the main explanation to the cause of the Iceman's death. In 2007, Swiss researchers using a CT-scan were able to establish the point where the arrow tore through the artery causing severe blood loss, scientists stating that this would have resulted in a rather quick death.
Although a lot of evidence has since been found in regards to the genetic makeup of the Iceman, the overall conclusion that most scientists agree on today is that he died due to the arrow wound. How he got that wound is widely debated throughout the whole of the world.