A four-plex in Redding caught fire just before 10 a.m. off of Churn Creek Road.
People were inside when the fire broke out in one unit, but everyone has been accounted for and there are no injuries.
According to Redding Fire they believe that the fire could have been electrical.
The fire was fully engulfed in one unit and has spread to the attic.
The fire is currently contained to the attic, but is not out yet.
They have detained one person for questioning. The cause of the fire is still under investigation.