LYNN – A fire official said investigators have not identified the cause of a fire that displaced 24 city residents early Sunday morning. But the official said investigators also have not ruled out that an electrical problem may have sparked the blaze.”The cause is undetermined at this time and they cannot rule out (an) electrical (cause),” Lynn District Fire Chief Jack Barry said late Monday afternoon, relaying the word from arson investigators.Firefighters responded at 1:53 a.m. Sunday to 11 Breed Square, just east of the intersection of Western and Summer streets, and found a three-story apartment building aflame. The second alarm was rung at 1:57 a.m. and the third at 2:02 a.m. Firefighters from three area departments responded to the scene to assist, while personnel from five area departments covered city stations during the incident.Firefighters rescued a mother and her two children from the third floor of the building. No residents were injured; but two firefighters suffered injuries.The American Red Cross helped 22 people from five families who were affected by the blaze, and the building was posted as uninhabitable on Sunday.