Jet Crash Likely Caused by Pilot Error and Loss of Oxygen

A private plane carrying three passengers and a pilot crashed in a Virginia forest on Sunday.
The primary theory for the cause of the crash is hypoxia, a condition resulting from depleted oxygen levels that can lead to confusion, unconsciousness and ultimately death.
Private planes can fly up to 45,000 feet, and oxygen systems or pressurization failures at high altitudes can quickly lead to hypoxia.
The pilot likely lost consciousness from hypoxia, causing the plane to continue flying on autopilot until running out of fuel and crashing.
Similar crashes caused by unresponsive pilots have occurred before, including the 1999 crash of a Learjet carrying professional golfer Payne Stewart.