The Madison Fire Department says a passerby helped alert firefighters to a garbage truck that was on fire downtown earlier this week. Firefighters were doing their routine fire code inspections east of the Capitol downtown when someone called their attention to a garbage truck that was pulled over on E. Johnson St. with a fire burning in the back. Firefighters with Engine Co. 3 went to check on the garbage truck and saw smoke coming from the top hatch, with the driver of the truck standing on top of the cab and using a fire extinguisher. Crews began fighting the fire after helping the garbage truck worker down from the cab and applied water to the garbage inside until they were confident the fire was out. Firefighters also removed items that burned inside the truck and soaked them. The truck was mostly carrying cardboard that was on its way to be recycled, officials said.