The construction schedule was accelerated, with one floor per day being completed by September 1961. The days were long, with crews working on the central cores from 4:30 a.m. to as late as 10:00 p.m. By having apartments ready by February 1962, developers could start renting them and paying off loans.

“The added costs from such an accelerated construction program,” said Charles Swibel, “will be offset by the effects of earlier occupancy and a reduction in interest paid on loans during the construction period.”

For two months in early 1961, construction of the west tower core was delayed because of work by the city on the nearby Dearborn Street bridge. But by the end of August, concrete had been poured for the 40th floor of the east tower core.

The goal was to have all of the apartments ready by September 1962.