The pilot, William Dieder, 58, of Cedar Grove, Wis., and the patient's wife, Ilomae Bialek, 75, were pronounced dead at the scene. The patient, John Bialek, 80, died after being transported to the hospital. The Bialeks are from Streamwood.
The co-pilot and a flight paramedic survived the crash and are being treated for non-life threatening injuries at Condell Medical Center in Libertyville.
The plane went down around 11 o'clock Monday night, just a few miles north of its destination, Chicago Executive Airport in Wheeling.
Calls to 911 reveal the first fear-fueled moments after the crash. "People are screaming there's a fire, maybe an explosion. It smells funny," the caller said. "OK, we're on the way," replied the dispatcher.
On Tuesday, investigators sifted through the wreckage of the twin-engine Piper Navajo plane scattered between homes in the heavily-wooded neighborhood.
"The tanks are compromised and where the tanks are there are no signs of fuel," said Ed Malinowski, National Transportation Safety Board.
The plane went down in a wooded lot between two homes. It broke into pieces, scattering debris and coming just 50 feet from John McGuire's home.
"What I heard really sounded like an 80 or 90 mile an hour wind, like a bunch of debris of the roof of the house. Got some skylights in the house. I could hear debris like hitting the glass," said McGuire.
Nearby resident Charlie Norwesh says he ran to the crash site just before 11 p.m. Monday night and beat back flames as he pulled the injured co-pilot to safety.
"I took my coat, and I was trying to smother it just to keep the oxygen away from it just long enough to get him out of the airplane," Norwesh said. "I just feel for the people that didn't make it."
Five people were on board the medical transport plane, which originated in Florida and was headed to Chicago Executive Airport in Wheeling. Along the way, the crew stopped in Georgia to refuel.
"I've heard that the pilot made a low fuel announcement, but I've not been able to confirm that. And I've requested tapes of that," said Malinowski.
Neighbors say the Bialeks had been living near West Palm Beach, Fla., but decided to fly Monday to be closer to family.
"They decided it might be better for them to go home. They live in the Chicago area. So rather than stay here - John was hospitalized - they would go back to the Chicago area," said Sylvia Knel, victims' Florida neighbor.
The crash is being investigated by the NTSB and the FAA. Investigators are trying to determine if weather was a factor in the deadly crash.