The preliminary cause...possibly arson-related...for that house fire early today on the Oklahoma City southside.

It apparently started around 2:30 a.m. as a passerby reportedly noticed flames coming from a two-story house in the 2400 block of SW 76th Street near I-240 and South Penn Avenue.

The person called the fire department and when they arrived they found flames and smoke coming from the building.

No one was inside and there was a real estate lockbox on the front door.

The initial feeling now is that someone may have come through the back door and started the fire.  Vagrants may have been in the area.

No word yet on a damage estimate.