PORTLAND, Ore. (AP) — Authorities say a person who was trying to stay warm in a makeshift shelter died in a fire in North Portland. Portland Fire & Rescue said Tuesday that firefighters responded about 7 a.m. to a fire underneath an overpass and found a makeshift structure on fire. Authorities say a 27-year-old escape the burning structure before crews arrived. Authorities say the person was badly burned and taken to a hospital burn center. The person died from their injuries a few hours later. Investigators believe the fire may have started by an improvised, propane-fed device that ignited materials used to insulate the space from the cold temperatures.