A plane crash is an incident in which an aircraft, usually a commercial airliner or private plane, collides with something or experiences some type of mechanical failure that causes it to come down unexpectedly. This can result in serious injury or loss of life for those on board and significant damage to property on the ground. Plane crashes are typically considered one of the most catastrophic types of transportation accidents due to their high fatality rates, though they remain relatively rare when compared with other modes of travel.