LYNN-Two alert police officers warned 24 Chase St. residents of a third-floor fire Monday afternoon before the blaze could spread through the building.Officers Andrew Beaver and Thomas Morley spotted smoke pouring from the roof of 24 Chase St. off Franklin Street at 1:45 p.m. and banged on the first floor apartment door, startling tenants.”They didn’t believe the house was on fire,” Beaver said.After evacuating members of building owner Luis Zepada’s family from the first floor, the pair alerted second-floor resident Octavia Fernandez, who lives in 24 Chase with her four children. Morley and Beaver saw smoke seeping underneath the third-floor door as they climbed the stairs to it.Third-floor residents Carlos and Madelin Zapeda were at work at the time of the fire and their children, ages 4 and 10, were at school. Firefighters were not sure if four or five people live on 24 Chase’s first floor.Fernandez wept, huddled in a quilt on a neighbor’s porch, while she watched firefighters finish extinguishing the fire.”I don’t know where I will go,” she said.Firefighters summoned the Red Cross to Chase Street to offer assistance services to the residents.Fire investigator David Legere said initial indications suggest the fire started near or in an electrical outlet in the children’s bedroom at the rear of the third floor.”What kept the fire from being any worse was a bedroom skylight. It burned through that and basically vented itself,” Legere said.He said city inspectors would check the building today to determine if the third floor apartment and a living area discovered in the basement meet city housing code.