A pregnant woman, her husband and her baby were rescued early Tuesday morning from a fire that consumed two apartments and displaced residents in another six units.A cigarette ignited an oxygen line and fueled a fire at 1215 E. Fifth St. No one was hurt. The fire started about 1:30 a.m., Carson City Battalion Chief John Arneson said. When firefighters arrived, the lower apartment was engulfed. Flames were “blowing out of every window and the doors,” he said. Flames also were reaching the unit directly above.“The first floor exploded, helping to get the second floor going,” Arneson said.The woman, her husband and the baby were rescued with the use of a ladder. Residents in all six units were displaced because the utilities were turned off and some of the undestroyed units have smoke damage; they will be livable once the utilities have been turned back on.The other two units were destroyed, and the Red Cross is helping the victims. Douglas County also brought in a unit to fight the blaze.No one was hospitalized, and an emergency source of oxygen was found for the woman whose oxygen tank exploded.