Carroll County Sheriff Troy Hofstetter said the fire started early Friday in the basement of the home near the small town of Plymouth. A mother, father, one of their children and two other young relatives died in the blaze.
Authorities have not released their identities.
Hofstetter says two other people escaped from the home, and one of them went to a neighbor's house and called 911 around 5 a.m. Both survivors were taken to a hospital. Hofstetter says he doesn't know their conditions.
Calling the fire "a strange one," he says the blaze was mainly contained to the basement and there was little damage to the outside of the house. He would not elaborate.