Firefighters have extinguished a blaze at an apartment building at 8 Pleasant St. in Westbrook less than an hour after it started.

Speaking at the scene, Westbrook Fire Chief Gary Littlefield said the fire appeared to have started on the outside of the building and spread inside. Littlefield said residents apparently were unharmed, but he didn’t know how many lived there.

Firefighters arrived at the scene about 6 p.m. Keith Cyr, who lives next door at the corner of Main and Pleasant streets, watched Monday evening as firefighters worked to secure the home. “There was smoke coming out of the third floor for awhile,” said Cyr.

Firefighters from Gorham, Windham and Scarborouth also responded.