DEFIANCE, Ohio (WOWO) — Two sisters were killed in an early morning house fire Tuesday in Defiance, authorities confirmed.

According to our partners in news at 21ALIVE, fire crews were dispatched around 4:15 a.m. to a residence in the 200 block of Ruth Ann Drive, where they arrived to find the home fully engulfed in flames. Officials said the structure was unstable, preventing firefighters from entering the house while the fire was actively burning.

According to the Defiance Fire Chief, the incident was initially handled as a rescue but shifted to a recovery operation around 8 a.m., once the fire was extinguished and conditions inside the home were deemed safe.

Three adult siblings lived in the residence. A brother told firefighters he was able to escape but could not re-enter the home because of the flames.

Firefighters later recovered the bodies of two women from inside the house. Authorities have not yet released their identities, pending notification of family members.

The cause of the fire remains under investigation.