Most TBI that results from blunt trauma occurs within the chest.[14] The most common tracheal injury is a tear near the carina or in the membranous wall of the trachea.[13] In blunt chest trauma, TBI occurs within 2.5 cm of the carina 40–80% of the time.[2] The injury is more common in the right main bronchus than the left, possibly because the former is near vertebrae, which may injure it.[2] Also, the aorta and other tissues in the mid chest that surround the left main bronchus may protect it.[15] Another possibility is that people with left main bronchus injuries are more likely to also have other deadly injuries and therefore die before reaching hospital, making them less likely to be included in studies that determine rates of injuries.[6]