An adult who fled the fire about 2 a.m. CST in the Depoy community of Muhlenberg County told first responders that most of the family remained inside the house, Trooper Stu Recke said. The remains of six people were found by midmorning, and investigators were searching for others and working to determine the cause of the blaze.
"Basically, it is a recovery effort," Recke said.
Recke said he didn't have names or exact ages, but indicated that the children ranged from teenagers to a toddler.
"We have every reason to believe that all nine of the victims are still in the home," Trooper Paul Blanton said.
Vanderbilt University Medical Center spokeswoman Dagny Stuart said an adult and a child were taken to the hospital in Nashville, Tenn., but she could not provide immediate details about their conditions.
Recke said a father and daughter survived the fire, but he was unsure of their condition.
The fire broke out in a single-family house just west of Greenville, which is about 130 miles southwest of Louisville in the state's western coal fields. Greenville had a population of just more than 4,000 people in 2010, census figures show.
Recke described the region as "a rural area where everybody knows everybody." The house is in a small neighborhood of single-family dwellings, trailers and farmland.
The side and roof of the small, white-wood frame house collapsed around the chimney. In front of the house, a white van stood on a concrete parking pad. At least five kids' bikes and a child's riding toy were strewn about the yard near a swing set.
Several first responders lived near the home and reported that the house was fully engulfed when they arrived, within minutes of getting the call, Recke said.
The Kentucky State Fire Marshal also had an investigator on the scene. Recke said it is too early to tell what caused the blaze but noted that temperatures in the area were in the teens and single-digits overnight.
This is Kentucky's third fire in a little more than a year that has killed five or more people. Last January, four children under 6 and their father were killed in a blaze near Pikeville in eastern Kentucky that also severely burned their mother. Authorities said the home lacked a smoke detector.
In March, a fire at a home in the southern Kentucky community of Gray killed a young couple and five children, the oldest of whom was 3.
The area of the latest fire was featured in the 1971 John Prine song "Paradise," about the impact of coal mining and what happens to the area around the Green River once the mining ends.
The song references Peabody Energy Corporation and a now-defunct town called Paradise.