IOWA CITY — An Iowa City home was heavily damaged by fire early Friday morning.Iowa City Fire Department crews were called to 1920 Prairie du Chien Rd. at 1:51 a.m. after a traveler on Interstate 80 reported seeing a house on fire near the Prairie du Chien Road Bridge. The sole occupant escaped before firefighters arrived, authorities said.Crews were unable to enter the house because of “heavy fire conditions and building collapse,” the fire department said.