The 80-year-old man killed in a small-plane crash this week died from a heart attack and not from injuries sustained in the crash, according to an autopsy.
Five people were on board the medical flight when it crashed Monday night in a wooded area in north suburban Riverwoods. Two people, including a co-pilot and paramedic, survived the wreck.
But John Bialek, being transported for an undisclosed medical issue, was killed along with his wife, 75-year-old Ilomae, and pilot William Didier of Cedar Grove, Wis..
The autopsy for John Bialek revealed he died of coronary atherosclerosis, which is a hardening and narrowing of the arteries that supply blood to the heart, according to the Chicago Tribune.
The Piper Navajo aircraft went down sometime between 10:45 p.m. and 11 p.m. Monday near Portwine Road and Orange Brace Road just north of the Lake County Forest Preserve.
The pilot reported "fuel problems" shortly before the plane crashed. The flight originated in West Palm Beach, Fla., and refueled in Jesup, Ga., according to fire officials.
The FAA and NTSB are investigating the cause of the crash.