JACKSONVILLE, Fla. -

Last month's fire that took the lives of a 53-year-old woman and her three grandchildren was officially ruled accidental Tuesday by the State Fire Marshal's Office.

The June 17 fire that destroyed the double-wide mobile home on Palmetto Street started in in one of the bedrooms, but investigators have not released specific details of its origin.

Sheila Swearingen, 53; Janet Fowler, 10 months; Rachel Fowler, 2; and Richard "Bubba" Fowler Jr., 4, all died as a result of the fire. Six-year-old Haddie Fowler was rescued from the fire by a 13-year-old who was riding by on his bicycle.  She was hospitalized, but released the next day.

IMAGES: Fire destroys home, takes 4 lives

The Fire Marshal's Office said the fire started in the bedroom adjacent to the living room. She said that is not the room the grandmother and infant Janet were in. They were in the master bedroom.