The residents are returning nearly three weeks after being flooded out by storms.
They lined up Saturday morning after the building's management group got an "all-clear" from the Chicago Fire Department.
Some residents had been able to reenter their apartments and condos last week to clean out refrigerators and make other preparations, but they could not live in the building until Saturday.
"Sleeping on couches and floors for the past month has not been fun," said resident Eddie Montesa.
River City's parking garage and water system flooded during heavy rainstorms on July 24th.
Building management says ComEd and a variety of service crews had to restore power, air conditioning, and water service to the building.