Workers evacuated off the roof of a building when a structure fire started on East Washington Wednesday night. Five workers were able to evacuate the roof of the Research Products building at the corner of Brearly and Main St. around 6:15 p.m., the Madison Fire Department said. The workers were able to self-evacuate to an adjacent building. Callers reported heavy smoke and flames coming from the roof of the building, according to MFD. Firefighters said the fire took about a half hour to get under control. No one was injured as a result of the fire, and the cause of the fire is still under investigation. A damage estimate was not given at this time.