An 11-year-old Medford girl was treated for smoke inhalation Monday after her family's home caught fire at about 7 p.m. in the 300 block of Columbus Avenue.

An 11-year-old Medford girl was treated for smoke inhalation Monday after her family's home caught fire at about 7 p.m. in the 300 block of Columbus Avenue.

The girl thought her older brother was still in his room when she saw the blaze in the family living room and rushed inside the smoke-filled corridors to search for him, said Medford Fire Investigator Randy Cooper. It was unclear whether she was inside or outside the home when the fire started.

Medford firefighters arrived on the scene just after 7 p.m., three minutes after 9-1-1 dispatchers received a call about the fire, and determined no one was inside the one-story apartment, Cooper said.

Her 12-year-old brother had gone to a friend's house to watch television without his sister's knowledge after the apartment's power had failed, Cooper said.

Her mother and mother's boyfriend also were away at the time of the fire doing laundry at a neighbor's house, Cooper said.

The girl was transported to Providence Medford Medical Center, where she was treated for smoke inhalation and released.

Medford firefighters with four fire engines quickly extinguished the blaze, keeping it confined to the living room, Cooper said.

What ignited the fire remains under investigation but so far is undetermined, he said. The blaze originated around the family's sofa, he said.

There were no smoke detectors in the home.

"If they had a working smoke detector, this probably wouldn't have happened," Cooper said. "We would have been able to take care of it much faster and saved the home."

The family was displaced as a result of heavy smoke and heat damage to the apartment. The American Red Cross supplied the family with money for food, clothing and lodging for three nights.

The fire caused about $20,000 in damage to the living room floor, ceiling, sofa and other furnishings for which the family had no rental insurance, Cooper said.

Reach reporter Paris Achen at 776-4459 or e-mail pachen@mailtribune.com.