The Lubbock County Sheriff's Office says the blaze was extinguished early Tuesday at a rural home just southeast of Lubbock.
Lt. Bryan Taylor says someone passing by reported the blaze around 11:30 p.m. Monday. He says investigators believe four adults died, but that more victims might be found in the rubble.
Taylor says authorities do not believe the fire involved foul play. The cause of the blaze, which also destroyed two nearby vehicles, has not been determined.
The National Weather Service says temperatures were in the upper 40s overnight in the Lubbock area.