An early February blaze that heavily damaged multifamily home on North Bow Street was sparked by careless smoking, fire officials said Wednesday. A woman living in a second-floor apartment at 16 North Bow St. fell asleep on a living room sofa while smoking, officials said. Multiple packs of Seneca Red filtered cigars were in the area where the fire started. The cigars are not required to be as fire standard-compliant as cigarettes are, according to a press release from the state Fire Marshal’s Office. The woman suffered serious facial and respiratory burns and was treated at a Boston hospital. Ten others were rescued from the home by first responders. “About one-third of fire deaths in Massachusetts are the result of fires started by smoking materials,” said state Fire Marshal Peter Ostroskey.