A building at the old Welco Lumbermill site in Marysville burned and collapsed late last night. An outbuilding at the old Welco Lumbermill site in Marysville burned and collapsed late last night. Firefighters responded just after 10 p.m. to the 1400 block of First Street and found “flames were clearly visible through the roof and sides of the abandoned building upon arrival, said Marysville Fire Marshall Tom Maloney. It took 30 minutes in defensive mode to get the fire under control. Four fire companies responded. Firefighters were concerned that transients might be inside the building because it has been unoccupied since Welco closed in 2007. "After the primary search we did not find anyone inside the building,” Maloney said. No injuries have been reported. The fire remains under investigation.