One person was injured in a fire that broke out overnight Saturday in a Janesville duplex, officials said. Janesville firefighters responded just after midnight to 1544 Beloit Avenue for reports of a residential fire, according to a release. Crews found a duplex with fire and smoke showing from the back of one of the units. Police said everyone was out of the structure, and firefighters put out the fire. The resident of one of the units was taken to Mercy Hospital and Trauma Center for non-life-threatening injuries, officials said. Residents from both units were displaced in the fire.