A fire caused extensive damage to a building in Downtown Redding Thursday morning. Redding Fire Department investigators are still trying to determine the cause of the fire at Oregon and Shasta Streets, which was well involved when firefighters arrived shortly before 6AM. A first alarm response was able to extinguish it within about a half hour but extensive mop-up and overhaul kept fire personnel on scene for 7 hours. A civilian occupant of the building suffered burns and was transported to a hospital. Damage to the $300,000 building is estimated at $100,000, plus another $50,000 worth of contents.