Perhaps the most emotional moment in the weeklong redesign occurred on Friday when Mr. Arad arrived at Kennedy International Airport on a flight from San Francisco and was taken to Hangar 17, where trade center artifacts are kept by the Port Authority of New York and New Jersey. Several of the people who accompanied the young architect on this visit said he was deeply moved.
The question of how such objects, including police cars, fire trucks, steel columns and parts of the television antenna, might meaningfully be incorporated into a memorial was unresolved in Mr. Arad's original design, which centered on two square voids, 30 feet deep, marking the outline and location of the twin towers.
It remains to be seen whether the public will embrace the solution of an underground Memorial Center of 60,000 to 100,000 square feet at the southwest corner of the memorial site, bounded by West and Liberty Streets. The plan also calls for about 250,000 square feet of additional cultural space above ground, at the northeast corner of the site, Fulton and Greenwich Streets.
Among the first people to see the finished design on Tuesday were members of the jury. "We do not view our selection of a winner as the end of the memorial," they wrote in a statement.
Before the revised memorial was completed, several members of the memorial program drafting committee that was formed last year by the development corporation expressed concern that Mr. Arad's design did not "convey historic authenticity," as the competition guidelines had specified. They had suggested the possibility of including surviving original elements from the trade center.
The Port Authority has decided to install dehumidification within the next week for certain parts of Hangar 17 at Kennedy Airport, including areas that contain the last column removed from the site.
It also intends to build additional wood and tent containment areas for the vehicles and sensitive, important objects like sections of the tower floors that were compressed and burned into molten, meteor-shaped objects.