The LifeFlight helicopter had taken a patient from Coffee County in south-central Georgia to a Savannah hospital and was returning when officials lost radio contract with it at 2:30 a.m., said George Ivey, a spokesman for Atlanta-based LifeFlight.
After sunrise, the helicopter was found in a thickly wooded, swampy area next to a cotton field near Sumner in southwest Georgia, he said.
The pilot, a flight nurse and a paramedic were killed.
The helicopter had been heading for its base in Sylvester, about 30 miles from the crash site, Ivey said.
Johnny Howard, 27, who lives less than a quarter mile from the site, said the helicopter flew over his house around 2:30 a.m.
"It was real low," he said. "I heard a thump-like noise, but I didn't think anything had happened until this morning."
All three bodies were recovered and were to be sent to the state crime lab in Moultrie, Tift County Sheriff Gary Vowell said.
The Coffee County patient was suffering from a cerebral hemorrhage and was listed in critical condition later Monday at St. Joseph's Hospital in Savannah, hospital spokeswoman Adrienne Garbe said. She declined to release the patient's name.
Ivey said LifeFlight operates two other helicopters, one in Atlanta and one in Forsyth County, north of Atlanta.