A two-alarm fire early Saturday morning that damaged a building undergoing renovation in downtown Spokane appears to be arson, a fire department spokesman said.

Spokane Fire Department crews were called to 819 W. Riverside Ave. at 3 a.m. Saturday and found heavy smoke and fire on both floors of the two-story building after they forced their way inside, Assistant Fire Chief Brian Schaeffer said Saturday afternoon.

Since the building was under construction, no furniture or other contents were present to fuel the flames, but the fire was burning heavily in the floors and walls, Schaeffer said. Someone started the fire on the first floor, he said.

“It appears that somebody broke into the back of the building,” he said.

Twelve crews responded and were able to keep the fire from destroying the building or spreading to the building next door that houses the sports bar 24 Taps. No firefighters were injured.

The investigation into the fire is ongoing.