Madison firefighters discovered a fire after responding to a carbon monoxide alarm on the near west side over the weekend. Madison Fire Department Cynthia Schuster said crews responded to a home near Gilmore and Gregory Streets around 11:20 p.m. Saturday. Schuster said homes in the area had a power surge and were without power, and many furnaces weren't working. The homeowner told crews they'd been without heat and had been running four space heaters for six and a half hours. Firefighters investigated and confirmed there was carbon monoxide on the second floor, and they also could smell burning wood. Crews found burning plaster and smoke from the second-floor ceiling. They then found smoldering insulation and burning wiring in the attic space, along with some structural components that were burned through.