Firefighters responded to a fire caused by discarded smoking materials at an apartment building in South Portland at 10 p.m. Sunday. No one was hurt in the incident.

According to Lt. Robb Couture, of the South Portland Fire Department, the fire at 70 Grandview Ave. initially started on a porch in the rear of the building, and extended into the structure. The fire went to a second alarm, with mutual aid from Portland and Scarborough. The porch and a utility room were heavily damaged by fire, with smoke and water damage to at least three of the four units.

Couture said the cause of the fire was inappropriately discarded smoking materials on the porch. Three of the four units in the apartment building were occupied. Couture said it is unknown how many people were in the building when the fire occurred. All residents evacuated safely, and working smoke detectors were present. There were no initial estimates of damage available.