A fire Saturday evening that tore through a vacant house on the 100 block of Penn Street in Tamaqua has been ruled accidental.

Jason Hartz, assistant chief of the Tamaqua Fire Department, said the blaze began at 146 Penn St.

“Immediately after we had the fire extinguished, a state police fire marshal was called to assist with the investigation,” Hartz said.

The fire marshal, he said, determined the fire started on the home’s exterior.

The property appeared to be “empty for some time” and was in “rough shape,” Hartz said. It suffered considerable damage, mostly to the rear of its first and second floors.

Hartz said the home is connected to 148 Penn St., which was also unoccupied at the time of the fire.

The property at 148 Penn St. had smoke damage, he said. Firefighters also had to break through a common wall to make sure that the fire hadn’t spread.