A house on Depot Square went up in flames Monday morning. Now fire officials are working to piece together what happened.

Ironton Fire Chief Tom Runyon said a two-story structure at 705 Depot Square, occupied by Misti Spencer, caught fire just before 4 a.m. Monday

Approximately 10 firefighters battled the blaze. Runyon said they remained on the scene for approximately three and one half hours.

"It appears the fire started downstairs and moved up the stairwell," Runyon said. "We went over and dug it out and we have our philosophies. Now we're waiting for the owner to come in so we can talk to her."

Runyon said the blaze did "substantial damage" and that the investigation into the fire is ongoing.

No one was injured in the fire.

Runyon said the occupant was not home at the time of the fire. When asked if anyone else was in the residence at the time of the fire, Runyon said investigators are looking into that.

State Fire Marshal investigators will visit Ironton Wednesday to review the case.