The fire early Tuesday morning at the old and abandoned Woodhaven Learning Center on Bearfield Road in south Columbia was started by trespassers, according to Gale Blomenkamp, an assistant fire chief for the Boone County Fire Protection District. Columbia firefighters were first on the scene about 2 a.m. They later handed the fire off to Boone County. A total of 10 units and 23 firefighters needed about 25 minutes to extinguish the blaze.