Columbus Fire was called to an apartment at West Broad Street and South Wayne Avenue at 4 a.m Thursday for a person having difficulty breathing. When firefighters arrived on scene they determined a carbon monoxide issue and several people were evacuated from the building. Officials say paramedics transported two people to OSU Wexner Medical Center, but both are expected to be OK. Firefighters also had to give a dog an oxygen mask treatment on the scene. A fire investigator was called to the scene to determine the cause of the carbon monoxide problem. This incident remains under investigation.