Chad Watson, 36, and a son, Kylie, 11, escaped the fire in Muhlenberg County, NBC News reported. Both were in critical condition at Vanderbilt University Medical Center in Nashville late Thursday.
Kentucky State Police identified the dead as Larae Watson, 35; Madison, 15; Kaitlyn, 14; Morgan, 13; Emily, 9; Samuel, 8; Raegan, 6; Mark, 4; and Nathaniel, 4.
Trooper Stuart Recke said the blaze spread quickly through the single-story house. Investigators identified the cause as a flammable item left close to an electrical heater.
Laura Bennett, who lives nearby, suggested the Watsons were more victims of the wintry weather that has spread far to the south. The temperature in Muhlenberg County bottomed out at 1 degree below zero early Thursday when it usually hovers just above freezing.
"We normally don't have weather like that," Bennett told NBC News. "They said when they was trying to put the fire out, the water was turning to ice."
Bennett said Samuel Watson was at her house a few hours before his death, playing with her daughter.