An alert tenant is credited with coming to the rescue of a neighbor whose apartment had filled with smoke from unattended food cooking on a stove Thursday night at the Terrace Apartments in Butler, authorities said.

The 59-year-old woman was crawling on the floor and somewhat disoriented when Butler firefighters found her about 11:15 p.m. inside the sixth-floor apartment on South Cliff Street.

Authorities did not identify the woman, who possibly suffered smoke inhalation and was taken to Butler Memorial Hospital. Her condition was not known this morning.

The fire department was called after a neighbor noticed a light haze of smoke in the hallway and heard the smoke detector alarm coming from the woman’s apartment.

The main alarm was not going off, fire officials said.

The neighbor tried to alert the woman but got no response.

Firefighters opened the locked apartment door with a master key but the chain was attached. They spotted the woman on the floor of the apartment, which was filled with heavy smoke.

The firefighters yelled to her and she was able to get up and remove the chain. They got inside and found a pan of scorched food on the still lit burner of a gas stove.