A woman was found dead inside her burning home Thursday in the eastern Iowa town of Williamsburg.

The cause of the fire, spotted by a passerby around 4:40 p.m., is under investigation. Firefighters from Williamsburg and nearby North English extinguished the fire and then found the body of the homeowner, 52-year-old Barbara McCune, inside.

An autopsy is being conducted by the Iowa State Medical Examiner’s Office. McCune’s brother, William McCune, was 39 when he died in a fire in his Williamsburg trailer home in February of 2010. Investigators ruled that fire an accident tied to the home’s wood burning stove.