At 0914 Pacific time, the aircraft was substantially damaged when it collided with terrain short of Runway 12R at the North Las Vegas Airport. The Airline Transport pilot experienced an incapacitation event during the flight and was the only fatality. The two passengers received minor injuries. Visual conditions prevailed. After takeoff, the pilot started feeling ill and became incapacitated. The passenger in the cockpits right seat took over flying the airplane and flew it to the North Las Vegas airport where it impacted terrain while on final approach to land.