Fire and smoke forced the evacuation of part of a children’s wing of the University of Iowa Hospitals and Clinics early this morning. Tom Moore, spokesman for the Iowa City health care facility, says the fire broke out in an exhaust room of the ventilation system and was discovered about 2:20 A-M.Moore says about three-dozen patients had to be moved from that pediatric unit, but they weren’t taken outside in the cold. Moore says there’s little damage and just a little cleanup to be done.The cause of the fire is under investigation.