Fire crews were investigating whether a residential fire Wednesday evening that forced two residents outside began in the fireplace or chimney.

They weren’t injured, but Harrison Twp. Fire Chief Mark Lynch said it was too early in the investigation to pinpoint the cause of the fire on Elm Hill Drive.

Crews were dispatched at about 7:30 p.m. on a report of a working structure fire. What they found was heavy smoke and flames coming from the back of the home, Lynch said.

The two residents had gotten out by the time fire crews arrived, he said, noting that they’ll have to stay elsewhere for the night because of the damage to the home.

Lynch estimated the damage to the structure and contents at $30,000 to $40,000.

“We’re looking into the fireplace, chimney” as a preliminary cause, Lynch said. “We’re not certain.”