(Hamilton, OH) -- The cause of a fire that badly damaged a house, early Saturday morning, is still unknown.

The blaze was reported around 4 AM, at 920 Sycamore Street, and the first units on the scene reported flames coming from the back of the house, and thick smoke coming from the windows on both the first and second stories. 

Firefighters searched neighboring buildings because there was a fear the flames would spread.  But, crews kept the fire contained.

Damage is estimated at $50,000.