Yakima firefighters said Tuesday they are stil investigating a fire that killed a woman at a Gordon Road apartment complex. Capt. Jeff Pfaff said the investigation is taking time because investigators hope to speak to as many residents as possible who were at the Friday fire at the Mesa Apartments. Yakima police on Tuesday mentioned in an unrelated arrest report that a woman told an officer her 3-year-old son had started the fire. However, Pfaff said investigators had not yet had a chance to fully investigate that claim and are not ready to reach any conclusions about the cause of the fire. Fire investigators are working with a Yakima police detective on their investigation, Pfaff said.