MATADOR, Texas — State fire authorities are investigating a New Year’s Day blaze in a mobile home in West Texas that left three people dead, including an infant.

Motley County Sheriff’s officials say a fire in a fireplace and small heaters were being used at the trailer home in Matador, about 70 miles (112.65 kilometers) northeast of Lubbock, but the state fire marshal’s office would look into finding a cause.

A relative of the victims says his nephew, the nephew’s fiancĂ©e and their 1-month-old child died in the blaze.

Three other people managed to flee the burning home. The sheriff’s office says the fire is not being investigated as a crime.