(WHAS11) -- Investigators say a fire in Knox County, Kentucky that killed two adults and five children burned so hot they cannot determine what caused it.
The fire happened on March 9 in the city of gray. The state fire marshal's office and Kentucky State Police say arson investigators could not nail down a cause because of severe damage to the home.
Officials have concluded that it was an accident.
The fire killed a 27-year-old man, his 22-year-old fiancee, a three-year-old, an eight month-old and three two-year-old children.