Madison firefighters were busy early Sunday fighting dumpster blazes at two student apartment buildings, with a dozen dumpsters destroyed and siding melted off the buildings. Flames were shooting 20 feet high, and melted siding went up three stories, according to a news release from the Madison Fire Department. The first fire was early Sunday at 12:19 a.m. in the rear of a 32-unit apartment building at 118 N. Brooks St., next to the Southwest Commuter Bike Path.