LAFAYETTE -- A man who was smoking a cigarette while using an oxygen system was badly burned Wednesday after he sparked a house fire, firefighters said, but a good Samaritan might have saved his life.

Sarah Falconer of El Cerrito was working at a nearby home when she noticed the smoke shortly after noon and heard a woman yelling for help, firefighters said.

"Sarah then climbed over three fences, one of which was an electric fence, and climbed down a hill to assist the two residents in distress," the department reported in a Wednesday evening news release. "Sarah bravely picked up a disabled resident and carried him from danger, taking him to arriving firefighters."

Firefighters responding to the 12:11 p.m. call at a home in the 700 block of Moraga Road saw smoke and flames coming from the rear of the home and found Falconer outside with the 71-year-old victim and another resident, authorities said. Falconer declined to be interviewed, fire officials said.

Firefighters extinguished the fire in about 10 minutes.

Investigators determined the fire erupted while the man was smoking while using an in-home oxygen system. The man, whose name was not released, was taken to Kaiser Permanente Walnut Creek Medical Center for treatment of second- and third-degree burns to his face and hands.

A portion of the road outside the victim's home was shut down from St. Mary's Road to Sky Hy Drive until about 1:45 p.m. while crews

No damage estimate was immediately available.

Reporter Katy Murphy contributed to this story. Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter. com/ nataliealund.