Janesville firefighters were on the job early Tuesday morning. They were called out at 4:41 a.m. on a report of a residential fire on the city’s near west side. The call was reported as a fire on an upstairs porch in the 800 block of McKinley Street. Officials say the residents of the three-unit building were able to extinguish most of the fire. The cause is likely careless use of smoking materials.