Illinois authorities have released the results of an autopsy on a passenger who died aboard an American Airlines flight to Chicago.
The Cook County medical examiner says the passenger suffered from an arterial blockage.
The 51-year-old man was found unconscious in an aisle seat Tuesday during a trip from Kansas City, Missouri.
An American Airlines spokesman says flight attendants administered oxygen and tried to revive the man with an automatic external defibrillator device. Authorities on the ground were alerted, and the flight was met by paramedics upon arrival.