Several emergency calls poured in early Saturday about a fire at White Oaks Apartments, a 62-unit building in Bayside, North Shore Fire and Rescue Department officials said, according to The Associated Press.
The fast-moving fire is thought to have begun on an upper floor, Fire Chief Robert Whitaker said.
More than a dozen individuals were saved and a few people who had minor injuries received medical treatment, officials said. No deaths were reported, according to Fox 6 Now.
The Fire and Rescue Department shared photos on Facebook, which showed responders at the scene and large plumes of smoke that were illuminated by the orange flames.
The Red Cross set up a shelter for residents in nearby Fox Point.
Bayside is about 11 miles north of Milwaukee.
The Associated Press contributed to this report.