NORWAY — Fire of undetermined origin ignited a porch on an apartment building at 21 Cottage St. on Tuesday night, causing an estimated $10,000 damage, fire Chief Dennis Yates said.

Elizabeth Macut escaped the apartment unharmed, he said.

Flames ignited the exterior wall and set a couch on fire, Yates said. The cause is under investigation, “but at this time it looks like it’s accidental,” he said.

An investigator from the State Fire Marshal’s Office is expected to visit the scene Wednesday, he said.

About two dozen firefighters from Norway, Paris, Oxford and Poland helped extinguish the blaze.

The 2½-story, wood-framed building with five apartments is owned by Peter Marcinuk, Yates said.