(Cincinnati, Oh.)-- The investigation into a fire that destroyed a $4 million mansion in January is still ongoing.

The Jan. 10 fire in the community of Indian Hill, swept through the 10,000-square-foot home that sat on five acres.


Fire crews say the home on Cunningham Road, was fully engulfed by the time they arrived. The size of the home took crews almost seven hours to extinguish the blaze.


The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives investigators are working with state and local fire Departments to find a cause. The Cincinnati Enquirer reports that Ohio's state fire marshal's office says it's not unusual for the cause of the blaze to remain undetermined, given the structures large size.


Ohio state law says, fire marshals are required to determine within 90 days if a fire involving more than $5,000 worth of property, was caused by arson. That means fire investigators face a deadline of April 10, to rule if the Jan. 10, fire was arson.


The home is owned by the Decker family, and no one from the family was home when the fire started.