SIOUX CENTER, Iowa (AP) – A Sioux City man is recovering after he was rescued when a trench he was digging near Sioux Center collapsed.  KTIV-TV in Sioux City says the accident happened on Thursday.  The Sioux County sheriff’s office says 20-year-old Nathaniel Christensen was working with a crew to dig the trench when the dirt collapsed on top of him.  He was rescued by his co-workers and emergency crews.  Christensen was taken to a local hospital and then flown to Mercy Medical Center in Sioux Center where he was in fair condition.