A house fire early Wednesday killed four people, including two children, just four days after an even deadlier blaze about 20 miles away.

A 10-year-old girl suffered serious burns in Wednesday's east Tennessee house fire, while four other people escaped without injury, said Bob Pollard of the state fire marshal's office.

Investigators hadn't determined the cause of the fire.

Investigators identified the dead as Connie Torres, 32, her boyfriend, Rafael Pena, and her daughters Karlissa Torres, 8, and Samantha Stephens, 12.

They were in a back bedroom of the one-story wood-frame house when the fire began shortly after midnight.

Another daughter in the room, 10-year-old Amanda Torres, was rescued by an off-duty police officer who lives nearby, Fire Chief Mike Brubaker said.

Officer Jon Yates got into the bedroom through a window and carried the girl outside. She was listed in serious condition with burns at Shriner's Hospital in Cincinnati.

Thick smoke kept Yates from returning to help the others, Newman said.

Other officers helped Pena's two brothers out another window. Torres' adult niece and her boyfriend also survived. "They were in a separate bedroom and they escaped on their own," Brubaker said.

Loudon, about 30 miles southwest of Knoxville, is about 20 miles from Rockwood, where a couple, their son and daughter and two children who were spending the night died Saturday in another house fire.

Tennessee has a per capita fire death rate twice the national average and second only to Mississippi, according to the fire marshal's office.