MADISON, Wis. -

A fire on Madison’s south side Sunday morning around 4:15 caused $15,000 in damage to a four-unit apartment building, officials said.

The exterior fire at 1125 Catalpa Circle involved two recycling carts and miscellaneous items stored next to the building, according to a release. Fire and smoke damaged the exterior wall, a door and two air conditioners.

A town of Madison firefighter driving on Badger Road saw and smelled the smoke, officials said. He followed the smoke, saw the fire burning next to the building and reported the fire.

Crews checked for any fire extension into the building and ventilated light smoke from the apartments, according to the release. No injuries were reported.

Officials said the cause of the fire is still under investigation.