A structure fire that broke out in Downtown Redding late Tuesday night is under investigation. A little after 11 O’clock Redding Fire Department was dispatched to 2134 Pine Street. The first arriving engine company found a two story building with heavy smoke showing, and they called a second alarm to bring the rest of the city’s resources. An aggressive attack was made and the fire was under control in 15 or 20 minutes. Mop-up continued for about 3 hours. Pine Street was closed for about 2 hours. Apparently no people were inside the building and the cause of the fire is not known. The structure was an old house that was being remodeled into apartments. Damage to the $300,000 building is estimated at $250,000.