At first glance, it seems that the riot of square white panels suddenly appeared on the base of One World Trade, but  photos from the past few weeks show that they were going up all along. Closeup shots taken today reveal metal bolts protruding out from the panels. The curtain wall fasteners for the metallic scrim?

Workers fasten panels to base.

Beneath the blue carriage on the east side of the building, a final section of the base awaits panels.

Closeup of the white panels.

Elsewhere, Tower Four continues to make progress at the southeast corner of the site.