Injuries to the tracheobronchial tree within the chest may occur due to penetrating forces such as gunshot wounds, but are more often the result of blunt trauma.[6] TBI due blunt forces usually results from high-energy impacts such as falls from height and motor vehicle accidents; the injury is rare in low-impact mechanisms.[2] Injuries of the trachea cause about 1% of traffic-related deaths.[4] Other potential causes are falls from high places and injuries in which the chest is crushed.[13] Explosions are another cause.[21]