How did ian somerhalder's character Boone die on lost?

Answer 1

Boone and Locke discovered a heroin runner's Beechcraft stuck high in a tree canopy. Boone climbs up into the aircraft and finds a working radio in the cockpit, which he uses to transmit a Mayday signal. He receives a response to his message by a man, later revealed to be Bernard Nadler of the tail-section survivors, but the aircraft unbalances and falls nose-first to the ground. Boone sustains severe injuries and, despite Jack's attempts to treat him, dies on November 2, 2004. Boone tries to pass a message to Shannon through Jack, but dies before he is able to finish the sentence

Answer 2

Boone and Locke discovered a light aircraft and Boone managed to climb into it and send a Mayday signal, which was picked up by Bernard Nadler, who was one of the survivors from the tail section of the flight.

The aircraft lost its balance and fell out of the tree with Boone sustaining severe injuries. Jack atttempted to revive him but failed and Boone died before he could complete his message for Shannon.